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With this dissertation, I present a human resources approach to entrepreneurship through selection and training of small-business owners in developing countries. Entrepreneurship is an important source of employment, innovation, and general economic prosperity (Autio, 2005; Walter et al., 2005; Reynolds et al., 2005; Kuratko, 2003). In developing countries, job creation through business ownership is especially important because job opportunities are limited (Walter et al., 2005; Mead & Liedholm, 1998). Strengthening the small business sector is one of the best ways to reduce poverty and increase economic growth (Birch, 1987). Thus, this dissertation adds to the scientific literature in taking a human resources approach to entrepreneurship: selecting and training entrepreneurs. Selection has widely been researched on in various scientific fields like human resource management, industrial-, work-, and organizational psychology, but only partly focusing on selection of entrepreneurs. Regarding training, there exists a fair amount of studies that focus on entrepreneurship education, but a lot of them suffer from substantial heterogeneity and methodological flaws (Glaub & Frese (2011); McKenzie & Woodruff (2013)). The dissertation combines the ideas of using selection procedures for entrepreneurs with the idea of teaching entrepreneurial skills.
A Matter of Connection: Competence Development in Teacher Education for Sustainable Development
(2021)
Based on a dual case study, this cumulative dissertation investigates how individual "education for sustainable development" (ESD) courses, as part of the teacher education programs at Leuphana University in Lüneburg/Germany and Arizona State University (ASU)/USA, actually foster students' ESD-specific professional action competence. Furthermore, this work sheds light on the link between learning processes and outcomes, to reveal which factors actually affect the achievement of ILOs and competence development. The findings of this study indicate that both courses under investigation eventually live up to their role and increased student teachers' competence and commitment to implement ESD in their future careers; yet, mainly due to their different thematic foci, to varying degrees. Additionally, the four Cs (personal, professional, social, and structural connections) were revealed as significant factors that support students' learning and should be considered when planning and designing course offerings in TESD, with the goal of developing students' knowledge, skills, and attitudes.
The computational analysis and the optimization of transport and mixing processes in fluid flows are of ongoing scientific interest. Transfer operator methods are powerful tools for the study of these processes in dynamical systems. The focus in this context has been mostly on closed dynamical systems and the main applications have been geophysical flows. In this thesis, the authors consider transport and mixing in closed flow systems and in open flow systems that mimic technical mixing devices. Via transfer operator methods, They study the coherent behavior in closed example systems including a turbulent Rayleigh-Bénard convection flow and consider the finite-time mixing of two fluids. They extend the transfer operator framework to specific open flows. In particular, they study time-periodic open flow systems with constant inflow and outflow of fluid particles and consider several example systems. In this case, the transfer operator is represented by a transition matrix of a time-homogeneous absorbing Markov chain restricted to finite transient states. The chaotic saddle and its stable and unstable manifolds organize the transport processes in open systems. The authors extract these structures directly from leading eigenvectors of the transition matrix. For a constant source of two fluids in different colors, the mass distribution in the mixer and its outlet region converges to an invariant mixing pattern. In parameter studies, they quantify the degree of mixing of the resulting patterns by several mixing measures. More recently, network-based methods that construct graphs on trajectories of fluid particles have been developed to study coherent behavior in fluid flow. They use a method based on diffusion maps to extract organizing structures in open example systems directly from trajectories of fluid particles and extend this method to describe the mixing of two types of fluids.
Heating is most important part of thermal energy demand, and accounts for large amounts ofenergy consumption in cold regions. Renewable energy sources will be of great importance inorder to cover future energy demands. However, their intermittency is rightly considered asinconvenient. Thus, a more effective management of demand, coupled with efficient storagesystems is required. Based on this perception, thermal systems coupled with electricityproduction have been efficiently designed, they are the so called “combined heat and power”(micro-CHP). Nonetheless, heat losses from the thermal part of their system lead to electricityfluctuation. Therefore, the use of micro-CHP in combination with a volume-efficient and nearlylossless heat storage system to counteract electricity fluctuations is a viable solution.The heat storage system in this work is based on reversible thermochemical reactions, suchas dehydration and hydration of inorganic salts, which exhibits very high energy density (up to628 kWh·m-3 of storage material). The chosen inorganic salt (SrBr2·6H2O) reacting with purewater vapour operates within a closed system. The objective of this work is to design a systemthat thermodynamically matches the combination with micro-CHP. Therefore, investigationshave been performed from the material at micro-scale to the system at lab-scale. Models weredeveloped on the basis of heat and mass transfer with chemical reaction and were done in orderto numerically analyse the system. Experiments were additionally performed to consolidate thenumerical tools for future studies. Characterization experiments have been designed and tested.Thermo-physical properties (thermal conductivity, specific heat capacity, permeability, chemicalkinetics) of the reactive salt were then determined to be used as parameters into the sodeveloped models.The numerical simulations lead to the time-space evolution of heating fluid, reactive bedtemperatures and reactor pressure. The originality of this study is to model the coupled heat andmass transfer with chemical reaction on a 3D geometry to be close to the reality. Results help tonumerically and experimentally analyse the thermochemical heat storage performances. Thebed energy density is experimentally found to be 531 kWh·m-3 of salt hydrate. Based on thecondensation temperature during the experimentation, a reactor energy density of 140 kWh·m-3and a storage capacity of 65 kWh with a thermal efficiency of 0.78 are obtained. This systemproves the recovery capacity of more than 2/3 of the input energy. Various aspects of design andrecommendation for optimisation aspect that could help during prototype development aretaken into account and addressed. Comparison simulation-experiment is then performed anddiscussed, showing encouraging results, even if limited at lab-scale.
Against the backdrop of aging populations, labor shortages, and a longer healthy life expectancy, there has recently been considerable discussion of the great potential that post-retirement activities hold for individuals, organizations, and society alike. This dissertation consists of three empirical papers investigating the life reality of active retirees in Germany. In addition, framework conditions and motivational structures that need to be considered in creating jobs for this group of workers are examined. The first paper identifies the prerequisites for productivity after retirement age and describes the changed nature of modern-day retirement. Current levels of post-retirement work are quantified by reference to German Microcensus data. The data show that adults continue to engage in paid employment beyond the applicable retirement age, with self-employment and unpaid work in family businesses making up the greatest share of post-retirement activities. Qualitative data collected from 146 active retirees (mean age = 67 years, standard deviation = 4) showed that the changes entailed in retirement include more flexible structures in everyday life. Content analysis revealed that reasons for taking up post-retirement activities were the desire to help, pass on knowledge, or remain active; personal development and contact with others; and a desire for appreciation and recognition. In addition, flexible working hours and the freedom to make decisions are evidently important aspects that need to be taken into account in creating employment activities for silver workers. The second paper extends the findings of the first paper by investigating the differences that respondents experienced between their former career job and their post-retirement activities, drawing on an additional quantitative sample of active retirees (N = 618, mean age = 69 years, standard deviation = 4). Factor analysis revealed differences in four areas: First, differences were identified in person-related variables, such as work ability. Second, differences were perceived in the scope of the job itself with regard to workers’ tasks, skills, or job function. Third, the perceived freedom of time allocation and flexibility in job practice distinguished between the silver job and the former career job. Fourth, differences were noted in perceived responsibility and in the significance of the activity. The third paper further examined how relevant personal motivational goals (achievement, appreciation, autonomy, contact, and generativity) as well as corresponding occupational characteristics of the silver job were related to life and work satisfaction in the quantitative sample (N = 661, mean age = 69 years, standard deviation = 4). Hierarchical regression analyses showed that the motivational goals of achievement, appreciation, autonomy, contact, and generativity significantly predicted life satisfaction, whereas only generativity predicted work satisfaction. With respect to the occupational characteristics, none of the situational predictors influenced life satisfaction, but opportunities to fulfill one’s achievement goals, to pass on knowledge, and to experience appreciation and autonomy predicted work satisfaction. The results suggest that post-retirement workers seem to differentiate between perceived life satisfaction and work satisfaction as two independent constructs. In conclusion, key motives for taking up post-retirement activities were generativity (the wish to help and pass on knowledge), but also personal development, appreciation, autonomy, and contact. The findings indicate that organizations should introduce flexible working hours, and offer silver workers advisory and freelance work. Providing freedom to make decisions and ensuring due appreciation of the contribution made by silver workers will lead to a fruitful interplay of silver workers and organizations. Future research should build on these findings by applying longitudinal designs and drawing on samples of retirees with more diverse educational and financial backgrounds. The papers of this dissertation echo the call for a new, more positive way of looking at the capacities of active retirees.
In this dissertation, advanced nonlinear control strategies and nonlinear minimum-variance observation are combined, in order to improve the estimation and/or tracking quality within control and fault detection tasks, for several types of systems from the fields of electromobility and conventional drivetrain technology that have some potential for sustainability or performance improvements. The application-specific innovations in terms of nonlinear Kalman filter methods are: (1) Improved state of charge estimation for Lithium-ion battery cells, powered by a novel self-adaptive EKF that uses a high-order polynomial curve fit as a decomposition of the uncertain nonlinear output equation with intentionally redundant bases, and with a reduced number of polynomial parameters that are adapted online by the EKF itself. (2) Online estimation of the time delay between two periodic signals of roughly the same shape that have pronounced uncorrelated noise, based on a fractional-order approximation of the transcendent transfer function of the time delay which is used as a model in a novel kind of EKF. (3) Using two (E)KFs (one for the linear subsystem and one for the nonlinear subsystem of a new kind of multi-stage piezo-hydraulic actuator) in a cascaded loop structure in order to reduce the computation load of the estimation, by appropriate 'interfacing' between the two observers (using one shared system model equation, among other aspects). - The innovations in terms of nonlinear control methods are powered by observation, as well: (1) Sliding mode velocity control of a DC drive that is subject to nonlinear friction and unknown load torques, enhanced by an equivalent control law, and with a new intelligent switching gain adaptation scheme (for reduced control chattering and, thus, less energy consumption and actuator wear), which is powered by Taylor-linearized model predictive control, which in turn requires observer-based disturbance compensation (by a KF with a double-integrator disturbance model) for model-matching purposes in order to function correctly. (2) Direct speed control of permanent-magnet three-phase synchronous motors that have a high power-to-volume ratio, based on sliding mode control in a rotating d,q coordinate system, with a new equivalent control method that exploits both system inputs and with a secondary sliding surface to ensure compliance with the current-trajectory of maximum efficiency for the required torque, and which works without measurement of the rotor angle (thanks to a new kind of EKF that estimates all states in the stationary α,β coordinate system, as well as the disturbance/load torque and its derivative). In all instances, improvements (compared to methods existing in the literature) in terms of control and estimation performance have been achieved and confirmed using simulation studies or real experiments.
Halogenated flame retardants (HFRs) have been applied since the 1960s in various industrial and consumer products to protect humans as well as private and public possessions. In the past decade polybrominated diphenyl ethers (PBDEs), formerly the major applied HFRs were widely restricted and adopted as Persistent Organic Pollutants (POPs) in the Stockholm Convention due to their adverse effects on humans and the environment as well as their ubiquitous occurrence in the global environment. Besides PBDEs, various alternative HFRs have been applied for decades as well, or were recently developed to replace PBDEs. However, their potential adverse properties, environmental distribution and fate are largely unknown. Therefore, this thesis addresses the global occurrence, distribution and transport of alternative HFRs versus PBDEs in the marine atmosphere and seawater toward the Polar Regions in order to examine their longrange atmospheric transport (LRAT) potential. This thesis presents the first data on alternative HFRs in the atmosphere of the marine environment and the Polar Regions. Alternative brominated flame retardants (BFRs), Dechlorane compounds and PBDEs were investigated in high-volume air and seawater samples taken along several sampling transects in the Atlantic Ocean, Pacific Ocean and Indian Ocean toward the Polar Regions of the Arctic and Antarctic. In addition, three sampling cruises were conducted in the German Bight, North Sea. Several alternative HFRs were detected in the global marine atmosphere and seawater with hexabromobenzene (HBB), pentabromotoluene (PBT), pentabromobenzene (PBBz), 2,3- dibromopropyl-2,4,6-tribromophenyl ether (DPTE) and Dechlorane Plus (DP) being the predominant compounds which were observed in concentrations similar or even higher than PBDEs. Total atmospheric concentrations ranged from <1 pg m-3 over the open oceans up to 42 pg m-3 over the East Indian Archipelago. Seawater concentrations ranged from <1 pg L-1 in open ocean seawater up to 21 pg L-1 in coastal regions, while estuarine concentrations reached up to 6800 pg L-1. Overall, the comparison revealed that alternative HFRs dominate versus PBDEs in air and seawater, both in coastal regions as well as the Polar Regions, showing a shift from PBDEs toward alternative HFR in the marine atmosphere and seawater. The distribution in the global atmosphere was strongly influenced by the proximity to potential source regions and the pathway of the sampled air masses. Highest concentrations were observed in continentally influenced air masses, while low background concentrations occurred during sampling of oceanic remote air masses. In general, Western Europe, East and Southeast Asia but also Africa were identified as source regions for the marine environment, especially for alternative HFRs as well as BDE-209. In contrast, relatively low peak concentrations of the PBDE congeners of the Penta- and OctaBDE mixtures under continental influence were observed, indicating limited emissions of legacy PBDEs. The dry air-seawater gas exchange estimation showed that the atmosphere is a source for seawater resulting in net deposition into the global oceans after atmospheric emissions and transport, both in coastal regions as well as in the open oceans. Besides atmospheric depositions, riverine discharge was shown to act as source for coastal environments. The investigation of sampling transects toward the Polar Regions revealed that several alternative HFRs – in particular HBB, PBT, DPTE, PBBz and DP – undergo LRAT toward the Polar Regions in an extent similar to PBDEs and, therefore, meet the LRAT criterion of POPs under the Stockholm Convention. DP was found to undergo LRAT attached to airborne particles whereby stereoselective LRAT differences were shown for the two DP stereoisomers. With respect to LRAT, the results of this thesis therefore imply that alternative HFRs – in particular HBB, PBT, DPTE and DP – aren’t suitable replacements for PBDEs, but chemicals of emerging global environmental concern and possible future POPs.
Die vorliegende Dissertation wendet ein theoretisches Modell zum Zusammenhang zwischen Wirtschafts- und Umweltleistung auf existierende und eigene empirische Untersuchungen an. Die auf Basis des Modells formulierten Hypothesen werden mit eigenen empirischen Daten aus Europa insbesondere mit Bezug auf betriebliche Umweltstrategien und auf input-orientierten bzw. output-orientierten Umweltschutz untersucht. Dies ermöglicht insbesondere eine Bewertung des Einflusses der Strategiewahl. Die empirische Untersuchung basiert auf zwei unterschiedlichen Datensätzen. Es werden zunächst empirische Daten zur Umweltleistung von Papierfirmen in verschiedenen Ländern (Niederlande, England, Deutschland und Italien) untersucht, und dabei bei einer output-orientierten Messung der Umweltleistung ein im wesentlichen negativer Zusammenhang zwischen Umwelt- und Wirtschaftsleistung ermittelt. Bei Verwendung eines input-orientierten Maßes für die Umweltleistung wird ein im wesentlichen insignifikanter Zusammenhang gefunden. In der zweiten empirischen Untersuchung wird im Rahmen einer Befragung von Unternehmen des verarbeitenden Gewerbes in England und Deutschland eine Unterscheidung von betrieblichen Umweltstrategien vorgenommen. Dabei erfolgt auf Basis der Kriterien des Environmental Shareholder Value eine Einteilung der Firmen in solche mit wertorientierten Umweltstrategien und solche ohne spezifische Wertorientierung. Auf Basis dieser Unterscheidung wird die aus der zentralen Fragestellung der Dissertation abgeleitete Hypothese untersucht, dass der Zusammenhang zwischen Umweltleistung und Wirtschaftsleistung für Unternehmen mit einer wertorientierten Umweltstrategie positiver ist als für solche ohne spezifische Wertorientierung des Umweltmanagements. Diese Hypothese wird dahingehend bestätigt, dass für Firmen mit wertorientierter Umweltstrategie ein weitgehend positiver Zusammenhang zwischen Umweltleistung und umweltbezogenen Dimensionen der Wettbewerbsfähigkeit nachgewiesen wird.
This dissertation includes an introduction and five empirical papers focusing on the educational and career decision-making process of individuals in Germany. The five papers embrace different determinants of educational and career decisions including school performance, social background, leisure activities as well as professional expectations, and contribute to the existing literature in this research area. Chapter 2 of this dissertation begins by analysing the nexus between students’ time allocation and school performance in terms of grades and satisfaction with their own performance in mathematics, the German language and a first foreign language, as well as overall achievement. This chapter looks at the heterogeneity of three important extracurricular activities: student jobs, sports and participation in music. Moreover, the heterogeneity of each activity is addressed by accounting for different types of the particular activity and differences in the number of years the activity has been pursued. For this purpose, data from the German SOEP, as a representative panel survey of private households and people in Germany, in particular cross-sectional survey data of 3388 students who are about 17 years old and enrolled in a German secondary school, were used. The main findings are that having a job as a student is negatively correlated with school performance, whereas participation in sports and music is positively correlated. However, the results reveal heterogeneity in each activity, especially with respect to intensity. Chapter 3 addresses the concrete post-school decision of school students, in particular whether to study or to enter the German VET system (Vocational Education and Training). It focuses on individual risk preferences and the social background of individuals and how these determinants affect the ultimate decision to enrol in university or to start an apprenticeship given the same level of qualification. For the empirical approach data from the German SOEP were used, in particular information on individuals' educational decisions between 2007 and 2013. The results indicate that (i) individual risk preferences do not have an overall effect on the real transition; (ii) privileged individuals are more likely to take up higher education; and (iii) compared to highly educated parents, parents without an academic background are less likely to guide their children into tertiary education, regardless of how much they support their children with their school work. Chapter 4 deals with the reconsideration of educational decisions in terms of early contract cancellations in VET. In particular, the effects of a second job on the intention to cancel a VET contract early are analysed for apprentices in Germany. For the empirical approach the representative German firm-level study "BIBB Survey Vocational Training from the Trainee's Point of View 2008", conducted by the Federal Institute for Vocational Education and Training (BIBB), is used. The survey contains 5901 apprentices that were interviewed during their second year of apprenticeship (205 schools, 340 classes, and 15 common occupations). Furthermore, it includes the design, procedures, basic conditions, and quality criteria of apprenticeships. The applied probit regressions show a higher intention to quit if apprentices require a secondary job to cover their living costs. In Chapter 5, new data on 191 apprentices from a vocational school, located in a northern German federal state, are used to validate the empirical results of Chapter 4. This chapter presents new insights into secondary-job-related burdens during apprenticeship. Due to limitations in the data, the applied empirical approach in Chapter 4 lacks to analyse how holding multiple jobs increases the intention to leave an apprenticeship early. Therefore, Chapter 5 includes the investigations of burdens related to the second job. The results indicate a lower intention to quit the apprenticeship if an apprentice holds a second job to cover living costs. However, secondary jobs are linked to lower quality of training, which, on the other hand, increases the intention to leave the apprenticeship early. Furthermore, the probability of secondary-job-related burdens increases with the number of working hours. Chapter 6 concludes the thesis by investigating subjective determinants of early contract cancellations in VET. It examines ten questions on what apprentices want to achieve and how unfulfilled expectations affect the intention to leave the apprenticeship early. The findings of this investigation contributes to the existing research on early contract cancellation. The questions considered include information on the performance, personal development, career development and prospects or position in society and their meaning to apprentices. For the research approach, the "BIBB Survey Vocational Training from the Trainee's Point of View 2008" is considered again. The probit and ordered probit regressions applied show significant effects of job characteristics that represent job security. The expectation of being retained after an apprenticeship and the encouragement to consistently train further decrease the intention to leave the apprenticeship early. Furthermore, women appear to be more affected by job security signals than men, but they also sort more often into occupations with lower retention probabilities. Consequently, this result may be an indication of occupational segregation rather than a sign of differences between sexes.
Analysis of User Behavior
(2020)
Online behaviors analysis consists of extracting patterns from server-logs. The works presented here were carried out within the "mBook" project which aimed to develop indicators of the quantity and quality of the learning process of pupils from their usage of an eponymous electronic textbook for History. In this thesis, the research group investigates several models that adopt different points of view on the data. The studied methods are either well established in the field of pattern mining or transferred from other fields of machine learning and data mining. The authors improve the performance of archetypal analysis in large dimensions and apply it to unveil correlations between visibility time of particular objects in the e-textbook and pupils' motivation. They present next two models based on mixtures of Markov chains. The first extracts users' weekly browsing patterns. The second is designed to process essions at a fine resolution, which is sine qua non to reveal the significance of scrolling behaviors. The authors also propose a new paradigm for online behaviors analysis that interprets sessions as trajectories within the page-graph. In this respect, they establish a general framework for the study of similarity measures between spatio-temporal trajectories, for which the study of sessions is a particular case. Finally, they construct two centroid-based clustering methods using neural networks and thus lay the foundations for unsupervised behaviors analysis using neural networks.
Online marketing, especially Paid Search Advertising, has become one of the most important paid media channels for companies to sell their products and services online. Despite being under intensive examination by a number of researchers for several years, this topic still offers interesting opportunities to contribute to the community, particularly because of its large economic impact and practical relevance as well as the detailed and widely unfiltered view of consumer behavior that such marketing offers. To provide answers to some of the important questions from advertisers in this context, the author present four papers in his thesis, in which he extends previous works on optimization topics such as click and conversion prediction. He applies and extends methods from other fields of research to specific problems in Paid Search. After a short introduction, the dissertation starts with a paper in which the authors illustrates a new method that helps advertisers to predict conversion probabilities in Paid Search using sparse keyword-level data. They address one of the central problems in Paid search advertising, which is optimizing own investments in this channel by placing bids in keyword auctions. In many cases, evaluations and decisions are made with extremely sparse data, although anecdotal evidence suggests that online marketing is a typical "Big Data" topic. In the developed algorithm presented in this paper, the authors use information such as the average time that users spend on the advertiser's website and bounce rates for every given keyword. This previously unused data set is shared between all keywords and used as prior knowledge in the proposed model. A modified version of this algorithm is now the core prediction engine in a productive Paid Search Bid Optimization System that calculates and places millions of bids every day for some of the most recognized retailers and service providers in the German market. Next, the author illustrates the development of a non-reactive experimental method for A/B testing of Paid Search Advertising activities. In that paper, the authors provide an answer to the question of whether and under what circumstances it makes economic sense for brand owners to pay for Paid Search ads for their own brand keywords in Google AdWords auctions. Finally, the author presents two consecutive papers with the same theoretical foundation in which he applies Bayesian methods to evaluate the impact of specific text features in Paid Search Advertisements.
The world wide population growth and the increasing water scarcity endanger more and more the human society. Water saving measures alone will not be sufficient to solve all associated problems. Therefore, people in arid countries might come back to any kind of water available. In this context the way people regard wastewater must change in terms that it has to be recognized as a water resource. The reuse of wastewater, treated and untreated, for irrigation purposes in agriculture is already established in some semi-arid and arid countries. Countries with absolute water scarcity like Israel might not only be forced to reduce their water consumption, but even to transfer reused water to other sectors. Concerns of authorities and the general public about potential health risks are completely understandable. The health risks of wastewater are mainly originating from pathogens which are negatively correlated with its treatment. Therefore, the quality of a wastewater effluent derived from mechanical-biological treatment can be further improved by additional treatment steps like soil aquifer treatment (SAT). This process is adopted at the Israeli Shafdan facility in the south of Tel Aviv. Conventionally treated wastewater is applied on surface basins from where it percolates into the coastal plain aquifer which supplies approximately one quarter of Israel ́s drinking water. After a certain residence time in the subsurface the water is recovered by wells surrounding the recharge area. Although the pumping regime creates a hydraulic barrier to the pristine groundwater, concerns exist that a contamination of the surrounding drinking water wells could occur. So far, little is known about the removal of organic trace pollutants during the SAT process in general and for the Shafdan site in particular. Consequently, the need arose to study the purification power of the SAT process in terms of the removal of organic trace pollutants. For this purpose reliable wastewater tracers are essential to be able to differentiate between degradation and sorption processes on the one hand and dilution with pristine groundwater on the other hand. Based on their chemical properties, their worldwide usage in a variety of foodstuffs and beverages, and first data about the fate and occurrence of sucralose, artificial sweeteners came into the focus as promising tracer candidates.
Thus, in the present work an analytical method for the simultaneous determination of seven commonly used artificial sweeteners in different water matrices, like surface water and wastewater, was developed (see chapter 2). The method is based on the solid phase extraction (SPE) of the analytes by a styrene-divinylbenzene (SDB) copolymer material, and the analysis by liquid chromatography-electrospray ionization tandem mass-spectrometry (LC-ESI- MS/MS). The sensitivity in negative ionization mode was considerably enhanced by postcolumn addition of the alkaline modifier tris(hydroxymethyl) aminomethane. In potable water, except for aspartame and neohesperidine dihydrochalchone, absolute recoveries >75 % were obtained for all analytes under investigation, but were considerably reduced due to matrix effects in treated wastewater. The widespread distribution of the artificial sweeteners acesulfame, saccharin, cyclamate, and sucralose in the aquatic environment was proven. Concentrations in two German wastewater treatment plant (WWTP) influents ranged up to 190 μg/L for cyclamate, several tens of μg/L for acesulfame and saccharin, and about 1 μg/L for sucralose. For saccharin and cyclamate removal rates >90 % during wastewater treatment were observed, whereas acesulfame and sucralose turned out to be very persistent. As a result of high influent concentrations and low removal rates in WWTPs, acesulfame was the dominant sweetener in German surface waters with concentrations up to 2.7 μg/L. The detection of acesulfame and sucralose in recovery wells in the Shafdan SAT site in Israel in the μg/L range was a promising sign for their possible use as anthropogenic markers. As acesulfame and sucralose showed a pronounced stability in WWTPs and were detected in recovery wells of the SAT site in Israel it became worthwhile to assess their tracer suitability compared to other organic trace pollutants suggested as anthropogenic markers in the past (see chapter 3). Therefore, the prediction power of the two sweeteners was evaluated in comparison with the antiepileptic drug carbamazepine (CBZ), the X-ray contrast medium diatrizoic acid (DTA) and two benzotriazoles (1H-benzotriazole (BTZ) and its 4-methyl analogue (4TTri)). The concentrations of these compounds and their ratios were tracked from WWTPs with different treatment technologies, to recipient waters and further to river bank filtration (RBF) wells. Additionally, acesulfame and sucralose were compared with CBZ during advanced wastewater treatment by SAT in Israel. Only the persistent compounds acesulfame, sucralose, and CBZ showed stable ratios when comparing influent and effluent
concentrations of four German WWTPs with conventional wastewater treatment. However, by the additional application of powdered activated carbon in a fifth WWTP CBZ, BTZ, and 4-TTri were selectively removed resulting in a pronounced shift of the concentration ratios towards the nearly unaffected sweeteners. Results of a seven months monitoring program along the rivers Rhine and Main showed an excellent correlation between CBZ and acesulfame concentrations (r2 = 0.94), and still good values when correlating the concentrations with both benzotriazoles (r2 = 0.66 - 0.82). In RBF wells acesulfame and CBZ were again the compounds with the best concentration correlation (r2 = 0.85).
Wind energy is expected to become the largest source of electricity generation in Europe's future energy mix. As a consequence, future electricity generation will be exposed to an increasing degree to weather and climate. With planning and operational lifetimes of wind energy infrastructure reaching climate time scales, adaptation to changing climate conditions is of relevance to support secure and sustainable energy supply. Premise for success of wind energy projects is the ability to service financial obligations over the project lifetime. Though, revenues(viaelectricity generation) are exposed to changing climate conditions affecting the wind resource, operating conditions or hazardous events interfering with the wind energy infrastructure. For the first time, a procedure is presented to assess such climate change impacts specifically for wind energy financing. At first, a generalised financing chain for wind energy is prepared to (qualitatively) trace the exposure of individual cost elements to physical climate change. In this regard, the revenue through wind power production is identified as the essential component within wind energy financing being exposed to changing climate conditions. This implies the wind resource to be of crucial interest for an assessment of climate change impacts on the financing of wind energy. Therefore, secondly, a novel high-resolution experimental modelling framework with the non-hydrostatic extension of the regional climate model REMO is set up to generate physically consistent climate and climate change information of the wind resource across wind turbine operating altitudes. With this setup, enhanced simulated intra-annual and inter-annual variability across the lower planetary boundary layer is achieved, being beneficial for wind energy applications, compared to state-of-the-art regional climate model configurations. In addition, surrogate climate change experiments with this setup disclose vertical wind speed changes in the lower planetary boundary layer to be indirectly affected by temperature changes through thermodynamically-induced atmospheric stability alterations. Moreover, air density changes are identified to occasionally exceed the net impact of wind energy density changes originating from changes in wind speed. This supports the consideration of air density information (in addition to wind speed) for wind energy yiel assumptions. Thirdly, the generated climate and climate change information of the wind resource are transferred to a simplified but fully-fledged financial model to assess the financial risk of wind energy project financing with respect to changing climate conditions. Sensitivity experiments for an imaginary offshore wind farm located in the German Bight reveal the long-term profitability of wind energy project financing not to be substantially affected by changing wind resource conditions, but incidents with insufficient servicing of financial obligations experience changes exceeding -10% to 14%. The integration of wind energy-specific climate and climate change information into existing financial risk assessment procedures would illustrate a valuable contribution to enable climate change adaptation for wind energy.
Organizational culture is widely acknowledged to be a driver of organizational effectiveness. However, existing empirical research tends to focus on investigating the links between individual, isolated culture dimensions and effectiveness outcomes. This approach is at odds with the theoretical roots of organizational culture and does not do justice to the complex reality that most organizations face. This issue is addressed by this dissertation, which is comprised of four studies. Study 1 investigated the psychometric quality and cultural equivalence of three culture measures in a German context, based on a sample of 172 employees in a bank. The results suggested that the German versions of the Denison Organizational Culture Survey and the Organizational Culture Profile performed satisfactorily, while results regarding the GLOBE survey fell short of expectations. Study 2 reviewed the literature on the link between culture and effectiveness with a focus on studies that treat organizational culture as a holistic phenomenon. The review yielded four kinds of holistic approaches (aggregation-based, agreement-based, moderation- or mediation-based, and configuration-based). Study 3 investigated how a change in organizational culture induced by an M&A project impacts employee commitment. Based on a sample of 180 employees in a German organization, the findings suggest that individuals perceive cultural change differently, that cultural stability is positively related to employee commitment, and that group-level leader-member exchange and individual self-efficacy moderate this relationship. Study 4 introduced a new theoretical perspective (set theory) and a novel methodology (fuzzy set qualitative comparative analysis) to the field of organizational culture. Across two samples (1170 employees in a financial service provider and 998 employees in fashion retailer), results indicated that culture dimensions do not operate in isolation, but jointly work together in achieving different effectiveness outcomes.
In response to the challenges of the energy transition, the German electricity network is subjected to a process of substantial transformation. Considering the long latency periods and lifetimes of electricity grid infrastructure projects, it is more cost-efficient to combine this need for transformation with the need to adapt the grid to future climate conditions. This study proposes the spatially varying risk of electricity grid outages as a guiding principle to determine optimal levels of security of electricity supply. Therefore, not only projections of future changes in the likelihood of impacts on the grid infrastructure were analyzed, but also the monetary consequences of an interruption. Since the windthrow of trees was identified a major source for atmospherically induced grid outages, a windthrow index was developed, to regionally assess the climatic conditions for windthrow. Further, a concept referred to as Value of Lost Grid was proposed to quantify the impacts related to interruptions of the distribution grid. In combination, the two approaches enabled to identify grid entities, which are of comparably high economic value and subjected to a comparably high likelihood of windthrow under future climate conditions. These are primarily located in the mid-range mountain areas of North-Rhine Westphalia, Baden-Württemberg and Bavaria. In comparison to other areas of less risk, the higher risk in these areas should be reflected in comparably more resilient network structures, such as buried lines instead of overheadlines, or more comprehensive efforts to prevent grid interruptions, such as structural reinforcements of pylons or improved vegetation management along the power lines. In addition, the outcomes provide the basis for a selection of regions which should be subjected to a more regionally focused analysis inquiring spatial differences (with respect to the identified coincidence of high windthrow likelihoods and high economic importance of the grid) among individual power lines or sections of a distribution network.
This doctoral thesis deals with the topic of organizational misconduct and covers the three salient research streams in this area by addressing its performance outcomes, antecedents, and preventive measures. Specifically, it is concerned with the question of how different forms of misconduct are reflected in the stock performance of related organizations, thereby, covering the three pillars of corporate sustainability environmental, social, and governance (ESG). Furthermore, it aims to conceptualize how individual cognitive biases may lead to misconduct, therefore, potentially representing an antecedent and how existing management control systems can be enhanced to effectively address specific forms of misconduct, respectively. To these ends, the author first reviews the research stream of stock price reactions to environmental pollution events in terms of the underlying research samples, methodological specifications, and theoretical underpinnings. Based on the findings of the systematic literature review (SLR), he performs three stock-based event studies of the Volkswagen diesel emissions scandal (Dieselgate), workplace sexual harassment (#MeToo accusations), and the 2003 blackout in the US to cover the three ESG dimensions, respectively. In line with the SLR, his event studies reveal substantial stock losses to firms involved in misconduct that are eventually even accompanied by a spillover effect to uninvolved bystanders. Then, the author reviews the extant literature conceptually to develop a framework outlining how moral licensing as an individual cognitive bias might lead to a self-attribution of corporate sustainability, a consecutive accumulation of moral credit, and a later exchange of this credit by engaging in misconduct afterward. Finally, he assesses existing workplace sexual harassment management controls, such as awareness training and grievance procedures critically in another conceptual analysis. Based on the shortcomings stemming from management controls' focus on compliance and negligence of moral duties, he introduces five specific nudges firms should consider to enhance their existing management controls and eventually prevent occurrences of workplace sexual harassment. Based on the six distinct articles within this doctoral thesis, the author outlines its limitations and point at directions for future research. These mainly address providing further evidence on the long-term performance effects of organizational misconduct, enriching our knowledge on further cognitive biases eventually leading to misconduct, and conceptualizing nudging beyond the use-case of workplace sexual harassment.
This thesis aims to contribute to a better understanding of the actual implementation of transdisciplinary research in sustainability science. Following three aims, this work likes to (1) contribute to the measurability of transdisciplinary research processes as well as their societal and academic outputs and impacts, to (2) demarcate transdisciplinary research from other modes of research in sustainability science and to (3) identify and examine the determinants that shape the contribution of transdisciplinary research to societal action for sustainable development and to scientific knowledge production. To serve these aims a mixed methods approach is applied that combines strong quantitative elements with in-depth qualitative analyses that integrate the perspectives of practitioners. This thesis provides a broad set of indicators to describe and assess transdisciplinary research that translate theoretical concepts form transdisciplinarity theory into observable variables. The indicators offer a holistic perspective on transdisciplinary research by representing research mode characteristics, societal as well as scientific outcomes of research projects and their specific context. To theoretically demarcate transdisciplinary research from other forms of research, a narrative literature review first elaborates the differences between "normal science", political use of scientific knowledge and transdisciplinarity in their underlying logics of problem definition, knowledge production and research utilization. Subsequently, these concepts were compared with perspectives and expectations of practitioners in the forest sector on integrative research settings. Moreover, a cluster analysis of data from 59 research projects identified five research modes that empirically demarcate ideal-typical transdisciplinary research from other research modes within sustainability science: (1) purely academic research, (2) practice consultation, (3) selective practitioner involvement, (4) ideal-typical transdisciplinary research and (5) practice-oriented research. Based on this finding, transdisciplinary research can be characterized as an intensive, but balanced involvement of practitioners. It incorporates not only the needs and goals of the practitioners but also their norms and values. Ideal-typical transdisciplinary research goes beyond mere consultatory research approaches and must be distinguished from what is conceptualized as applied research. Regression analysis of 81 research projects and statistical group comparisons of the five research mode clusters show that societal and academic outputs and impacts vary with specific project characteristics and combinations of project characteristics defined as research modes. The findings indicate that more interactive research modes reach more societal impacts. In particular, the involvement of practitioners in early project phases and the targeted dissemination of the research results positively affect societal impacts. This finding also aligns with practitioner expectations on integrative research and research utilization, provided by qualitative analysis. Moreover, the quantitative results show that scientific outputs and impacts decrease with the intensity of interactions, indicating a trade-off between societal and scientific outcomes and impacts. Overall, the empirical results of this thesis support the claimed effectiveness of transdisciplinary research in providing societally relevant, applicable knowledge and encourage further funding of transdisciplinary research by funding agencies.
Assessment of forest functionality and the effectiveness of forest management and certification
(2021)
Forest ecosystems are complex systems that develop inherent structures and processes relevant for their functioning and the provisioning of ecosystem services that contribute to human wellbeing. With increasing climate change impacts, especially regulating ecosystem services such as microclimate regulation are ever more relevant to maintain forest functions and services. A key question is how forest management supports or undermines the ecosystems’ capacity to maintain those functions and services. The main objective of this thesis is the development of a concept to assess the functionality of forests and to evaluate the effectiveness of forest ecosystem management including certification. An ecosystem-based and participatory methodology, named ECOSEFFECT, was developed. The method comprises a theoretical and an empirical plausibility analysis. It was applied to the Russian National FSC Standard in the Arkhangelsk Region of the Russian Federation - where boreal forests are exploited to meet Europe's demand for timber. In addition, the influence of forestry interventions on temperature regulation in Scots pine and European beech forests in Germany was assessed during two extreme hot and dry years in 2018 and 2019. Microclimate regulation is a suitable proxy for forest functionality and can be applied easily to evaluate the effectiveness of forest management in safeguarding regulating forest functions relevant under climate change. Thus, the assessment of forest microclimate regulation serves as convenient tool to illustrate forest functionality. In the boreal and temperate forests studied in the frame of this thesis, timber harvesting reduced the capacity to self-regulate forests’ microclimate and thus impair a crucial part of ecosystem functionality. Changes in structural forest characteristics influenced by forest management and silviculture significantly affect microclimatic conditions and therefore forest ecosystems' vulnerability to climate change. Canopy coverage and the number of cut trees were most relevant for cooling maximum summer temperature in pine and beech forests in northern Germany. The Russian FSC standard has the potential to improve forest management and ecological outcomes, but there are shortcomings in the precision of targeting actual problems and ecological commitment. It is theoretically plausible that FSC prevents logging in high conservation value forests and intact forest landscapes, reduces the size and number of clearcuts, and prevents hydrological changes in the landscape. However, the standard was not sufficiently explicit and compulsory to generate a strong and positive influence on the identified problems and their drivers. Moreover, spatial data revealed, that the typical regular clearcut patterns of conventional timber harvesting continue to progress into the FSC-certified boreal forests, also if declared as "Intact Forest Landscape". This results in the need to verify the assumptions and postulates on the ground as it remains unclear and questionable if functions and services of boreal forests are maintained when FSC-certified clearcutting continues.The analysis of satellite-based data on tree cover loss showed that clearcutting causes secondary dieback in the surrounding of the cleared area. FSC-certification does not prevent the various negative impacts of clearcutting and thus fails to safeguard ecosystem functions. The postulated success in reducing identified environmental threats and stresses, e. g. through a smaller size of clearcuts, could not be verified on site. The empirical assessment does not support the hypothesis of effective improvements in the ecosystem. In practice, FSC-certification did not contribute to change clearcutting practices sufficiently to effectively improve the ecological performance. Sustainability standards that are unable to translate principles into effective outcomes fail in meeting the intended objectives of safeguarding ecosystem functioning. Clearcuts that carry sustainability labels are ecologically problematic and ineffective for the intended purpose of ecological sustainability.The overexploitation of provisioning services, i.e. timber extraction, diminishes the ecosystems' capacity to maintain other services of global significance. It also impairs ecosystem functions relevant to cope with and adapt to other stresses and disturbances that are rapidly increasing under climate change.
This dissertation presents an analysis of the relations to self and technology that emerge from and in the use of self-tracking technologies. The ethnographical study, combined with the Grounded Theory approach and a media analysis, demonstrates the complex intertwining or duality of control and care towards oneself that emerge or become possible in and through the application of ST technologies. ST devices assist in strengthening one's health and well-being in a playful way, building and maintaining a positive self-feeling, self-image and agency, and discovering unknown abilities and potentials within oneself. The ST technologies used provide orientation through complexity-reducing visualizations, highlighting patterns, and trend progression. They challenge through self-overload, dissatisfaction when not achieving goals, self-deception and distraction, narcissism and even loss of control - internally through compulsion to control as well as externally through loss of data otection and exploitation of private data by third parties, as well as handing over responsibility (in the form of decisions) to technology (algorithms) instead of self-responsibility. These two seemingly opposed yet concurrently existing self-relations reflect the dynamic between today's demands for self-responsibility (in health and performance terms) and the need for self-care and guidance for the many relevant, sometimes daily, decisions. They balance possibly existing tensions and ambiguities between the modes of self-relations that at first glance seem to be opposed and yet ultimately are jointly oriented towards the same goal, namely to master one's life (life maintenance) and to be in balance. The self-relations described in this thesis are supported, reinforced, or enabled by ST technology (and practice). Three different roles that ST technology can take in self-care and self-control were elaborated: technology as a means, a counterpart, and a promise. In relation to technology, another dialectic is visible, which shows the apparent contrast between its conception as a tool and means to achieve something and the approach to technology as an intimate counterpart (partner, nanny, coach) and a promise of salvation. The relationship with technology seems to intensify in and through the ST experience and takes on or is assigned a partner-like role by the users. Finally, the results indicate that the concept of (self-)optimization, contrary to its etymological meaning of a logic of increase, can also be understood differently, namely balancing. In this context, optimization does not necessarily mean the fastest, the highest, the strongest, but something that is achievable and satisfactory for the self - within the framework of the given and the desired. At the same time, the optimization understood as harmonizing and balancing in self-tracking becomes a lifelong task that, in principle, can never be completed because with the addition of new vital areas in life and throughout a lifetime also the individually understood and conceived balance often shifts.
Water is an essential natural resource, yet we are experiencing a global water crisis. This crisis is first and foremost a crisis of governance rather than of actual physical resources. Capacities of single, unitary states are severely challenged by the complex, multi-scalar, and dynamic structure of contemporary problems in water resource management. New modes of governance stress the potential of public participation and scalar restructuring for effective and legitimate environmental decision-making. However, a lack evidence on the actual implementation and instrumental value of novel governance modes stands in stark contrast to the strong beliefs and assumptions that often see these being propagated as ´panaceas´ or ´universal remedies´. With this doctoral dissertation I aim to contribute to a deeper understanding of the implementation and performance of public participation and scalar restructuring in environmental governance, and particularly to engage in systematic research into the contextual factors that shape the performance of such governance innovations. Based on the conceptual approaches of participatory, multi-level governance and scale, I advance a conceptual framework specifying mechanisms and important contextual factors describing the potential of participation and rescaling to impact on the efficacy of environmental decision-making. Applying this framework, I employ a mixed-methods approach combining qualitative, quantitative, set-theoretic, and review methods, with the aim of maximising the validity of results. Drawing on the institutional frame of the European Water Framework Directive (WFD), I first assess the extent and conditions under which participation and rescaling are actually implemented in the European water resource management regime. Subsequent analyses examine whether these governance shifts, where implemented, actually lead to environmentally effective and legitimate political decisions, and foster social outcomes. Results indicate that actual changes in governance structures remain modest, whereas previous institutional structures and experiences prove rather durable. Hence, despite recent shifts distributing authority towards alternative actors and scales, the state has persisted in its role as central authority in the European water resource management regime. To the extent that they were implemented, public participation and rescaling were generally positively related with the environmental effectiveness and legitimacy of political outcomes. The analysis provides a context-sensitive understanding, by unravelling the supposedly linear relationship between governance inputs and outputs to develop a more nuanced picture of the governance process rather as a composition of multiple, interdependent causal mechanisms that, depending on their actual configuration, lead to various outcomes. In this way, particularly the tension between legitimacy and effectiveness of political outcomes is disentangled, with both being seen as the result of distinct but interrelated properties of the governance system and its contextual circumstances. The thesis furthermore provides insights of practical and policy relevance, highlighting the need and potential to take a context-sensitive perspective in policy design and decision-making. The framework paper and the Ph.D. thesis thus together enhance academic understanding of environmental governance and its potential contributions to sustainability transitions.
Tropical ecosystems are critical for biodiversity conservation and local people’s livelihood sustenance. However, these ecosystems are under high pressure from land-use and land cover (LULC) change, which is further projected to intensify and increase rapidly, thereby affecting biodiversity and the provisioning of vital ecosystem services (ES). It is thus important to understand how LULC might change in the future and how such changes could affect biodiversity and ES provisioning in a given landscape of tropical ecosystems. Scenario planning has become an increasingly popular tool and technique to produce narrative scenarios of the future landscape change. Thus, quantifying changes under different land-use scenarios could be a means to elucidate the synergies and trade-offs within the scenarios. In this dissertation, the author examines the future of biodiversity and ES provisioning for different plausible land-use scenarios in southwestern Ethiopia. First, he translates four future plausible narrative social-ecological land-use scenarios ("Gain over grain", "Coffee and conservation", "Mining green gold" and "Food first") developed for southwestern Ethiopia by participatory scenario planning into spatially explicit LULC scenario maps. Results showed distinct LULC changes under each scenario. Second, the author investigates the impact of these land-use scenarios on biodiversity by specifically modelling woody plant species richness in farmland and forest. Both indicators of human disturbance and environmental conditions were used. Third, he also investigates the effect of these land-use scenarios on woody plant-based ES provisioning by combining woody plant species with household surveys on how woody plants were used by the local community. He models and predicts the current and future availability of woody plant-based ES under the four scenarios of landscape change. Overall, the findings of this dissertation show the importance of integrating future land-use mapping with participatory, narrative-based scenarios to assess the social-ecological outcomes of alternative futures. The spatially explicit maps of LULC change, biodiversity and ES (at different scales) could be used as a valuable input to support stakeholders and decision-makers to weigh the advantages and disadvantages of different development trajectories on ecosystems and human well-being and to avoid or minimize future undesirable consequences. To this end, apart from the benefits of coffee production under "Mining green gold" and crop production under "Food first" scenarios, the findings under these scenarios of large-scale agricultural intensification point to a potentially high loss of biodiversity and ES. These two scenarios could have a negative long-term impact on ecosystems and human well-being. Finally, the "Coffee and conservation" scenario, which involves the creation of a new biosphere reserve, appears to be the most sustainable scenario. This scenario could result in a sustainably managed, diversified landscape which could make major contributions to biodiversity conservation and human well-being in the region and beyond.
Traditional farming landscapes typically support exceptional biodiversity. They evolved as tightly coupled social-ecological systems, in which traditional human land-use shaped highly heterogeneous landscapes. However, these landscapes are under severe threats of land-use change which potentially pose direct threats to biodiversity, in particular through land-use intensification and land abandonment. Navigating biodiversity conservation in such changing landscapes requires a thorough understanding of the drivers that maintain the social-ecological system. This dissertation aimed to identify system properties that facilitate biodiversity conservation in traditional farming landscape, focusing specifically on birds and large carnivores in the rapidly changing traditional farmland region of Southern Transylvania, Romania. In order to identify these properties, I first examined the effects of local and landscape scale land-use patterns on birds and large carnivores and how they may be affected by future land-use change (Chapters II-V). Second, to gauge the role of particular traditional land-use elements for biodiversity I focused on the conservation value of traditional wood pastures (Chapters VI-VIII). Third, I took a social-ecological systems approach to understand how links between the social and ecological parts of the system affect human-bear coexistence (Chapters IV and IX). Bird diversity was supported by the broad gradients of woody vegetation cover and compositional heterogeneity. Land-use intensification, and hence the loss of woody vegetation cover and homogenization of land covers, would thus negatively affect biodiversity. This was especially evident from predictions on the distribution of the corncrake (Crex crex) in response to potential future land cover homogenization. Here, a moderate reduction of land cover diversity could drastically reduce the extent of corncrake habitat. Further results showed that the brown bear (Ursus arctos) would mainly be affected by land-use change through the fragmentation of large forest blocks, especially if land-use change would reduce habitat connectivity to the presumed source population in the Carpathian Mountains. Moreover, this dissertation revealed that large carnivores (brown bear and wolf, Canis lupus) may have important and often ignored roles in structuring the ecosystem of traditional farming landscapes by limiting herbivores. Wood pastures were found to have a high conservation value. The combination of low-intensity used grasslands with old scattered trees provided important supplementary habitat for different forest species such as woodpeckers and the brown bear. Worryingly, current management of wood pastures differed from traditional techniques in several aspects, which may threaten their persistence in the landscape. The majority of people had a positive perception on human-bear coexistence. The use of traditional sheep herding techniques combined with the tolerance of some shepherds to occasional livestock predation facilitated coexistence in a region where both carnivores and livestock are present. More generally, the genuine links between people and their environment were important drivers of people´s positive views on coexistence. However, perceived failures of top-down managing institutions could potentially erode these links and reduce people´s tolerance towards bears. Through the consideration of two different animal taxa, this dissertation revealed six important system properties facilitating biodiversity conservation in traditional farming landscapes. Similar proportions of the main land-use types (arable land, grassland, and forests) support species richness at the regional scale possible through habitat connectivity and continuous spill-over between land-use types. Heterogeneous landscapes can further support biodiversity through complementation and supplementation of habitat at the landscape scale. Gradients of woody vegetation cover and heterogeneity, supported biodiversity at both local and landscape scales possibly through the provision of a wide range of resources. The heterogeneous character of the landscape is tightly linked to traditional land-use practices, which also maintain specific traditional land-use elements and facilitate human-carnivore coexistence. Top-down limitation of large carnivores on herbivores possibly enhances vegetation growth and tree regeneration. The genuine links between humans and nature support human-bear coexistence, and these links may form the core of people´s values and sustainable use of natural resources.
Protected areas are an essential tool for conserving biodiversity. However, their ecological effectiveness is contested and their capacity to resist human pressures differ. This dissertation aimed to assess the ecological effectiveness of different protection levels (from strict to less strictly protected: national park, game reserve, forest reserve, game-controlled area, and unprotected areas) in biodiversity (both mega diverse butterflies and mammals), maintaining habitat connectivity, and reducing anthropogenic threats at the wider landscape in the Katavi-Rukwa Ecosystem of southwestern Tanzania. To achieve this overarching goal, the researcher employed an interdisciplinary approach. First, he analyzed butterfly diversity and community composition patterns across protection levels in the Katavi-Rukwa Ecosystem. He found that species richness and abundance were highest in the game reserves and game-controlled areas, intermediate in the forest reserves, national park and unprotected areas. Species composition differed significantly among protection levels. Landscape heterogeneity, forest cover, and primary productivity influenced species composition. Land-use, burned areas, forest cover, and primary productivity explained the richness of species and functional traits. Game reserves hosted most indicator species. Second, the author modelled the spatial distribution of six large mammal target species (buffalo Syncerus caffer, elephant Loxodonta africana, giraffe Giraffa camelopardalis, hartebeest Alcelaphus buselaphus, topi Damaliscus korrigum, and zebra Equus burchellii) across environmental and protection gradients in the Katavi-Rukwa Ecosystem. Based on species-specific density surface models, he found relatively consistent effects of protection level and land-use variables on the spatial distribution of the target mammal species: relative densities were highest in the national park and game reserves, intermediate in forest reserves and game-controlled areas and lowest in un-protected areas. Beyond species-specific environmental predictors for relative densities, the results highlight consistent negative associations between relative densities of the target species and distance to cropland and avoidance of areas in proximity to houses. Third, the author examined temporal changes in land-use, population densities and distribution of six large mammal target species across protection levels between 1991 and 2018. During the surveyed period, cropland increased. Wildlife densities of most, but not all target species declined across the entire landscape. Based on logistic regression models, target species preferred the national park over less strictly protection levels and areas distant to cropland. Fourth, he quantified land-use changes, modelled habitat suitability and connectivity of elephant over time across a large protected area network in southwestern Tanzania. Based on analyses of remotely-sensed data, cropland increased from 7% in 2000 to 13% in 2019. Based on ensemble models, distance from cropland influenced survey-specific habitat suitability for elephant the most. Despite cropland expansion, the locations of the modelled elephant corridors (n=10) remained similar throughout the survey period. Based on circuit theory, the author prioritizes three corridors for protected area connectivity. Key indicators of corridor quality varied over time, whereas elephant movement through some corridors appears to have increased over time. Overall, this dissertation underpins differences in ecological effectiveness of protected areas within one ecosystem. It highlights the need to utilize a landscape conservation approach to guide effective conservation across the entire protection gradient. It also suggests the need to enforcing land use plans and having alternative and sustainable forms for generating income from the land without impairing wildlife habitat.
Through the expansion of human activities, humanity has evolved to become a driving force of global environmental change and influences a substantial and growing part of natural ecosystem trophic interactions and energy flows. However, by constructing and building its own niche, human distance from nature increased remarkably during the last decades due to processes of globalization and urbanization. This increasing disconnect has both material and immaterial consequences for how humans interact and connect with nature. Indeed, many regions across the world have disconnected themselves from the productivity of their regional environment by: (1) accessing biological products from distant places through international trade, and (2) using non-renewable resources from outside the biosphere to boost the productivity of their natural environment. Both mechanisms allow for greater resource use then would be possible otherwise, but also involve complex sustainability challenges and lead to fundamentally different feedbacks between humans and the environment. This dissertation empirically investigates the sustainability of biophysical human-nature connections and disconnections from a social-ecological systems perspective. The results provide new insights and concrete knowledge about biophysical human-nature disconnections and its sustainability implications, including pervasive issues of injustice. Through international trade and reliance on non-renewables, particularly higher-income regions appropriate an unproportional large share of global resources. Moreover, by enabling seemingly unconstrained consumption of resources and simultaneous conservation of regional ecosystems, increasing regional disconnectedness stimulates the misconception of decoupling. Whereas, in fact, the biophysically most disconnected regions exhibit the highest resource footprints and are, therefore, responsible for the largest environmental damages. The increasing biophysical disconnect between humans and nature effectively works to circumvent limitations and self-constraining feedbacks of natural cycles. The circumvention of environmental constraints is a crucial feature of niche construction. Human niche construction refers to the process of modifying natural environments to make them more useful for society. To ease integration of the chapters in this thesis, the framework paper uses human niche construction theory to understand the mechanisms and drivers behind increasing biophysical disconnections. The theory is employed to explain causal relationships and unsustainable trajectories from a holistic perspective. Moreover, as a process-oriented approach, it allows connecting the empirically assessed states of disconnectedness with insights about interventions and change for sustainability. For a sustainability transformation already entered paths of disconnectedness must be reversed to enable a genuine reconnection of human activities to the biosphere and its natural cycles. This thesis highlights the unsustainability of disconnectedness and opens up debate about how knowledge around sustainable human niche construction can be leveraged for a reconnection of humans to nature.
The German market for corporate bonds has experienced an unprecedented growth over the last decade. As a growing number of German firms have seized the opportunity to issue debt securities to the market, the need arises to evaluate their attempts to provide bondholders with private corporate information. This doctoral thesis centers on a research interest concerning the extent and effectiveness of corporate disclosure directed at the German bond market. It delivers unprecedented insights into bondholder relations practices and is thought to establish this topic as a research field that is complementary to previous work on shareholder-related disclosure. Taking information asymmetries between firms and bondholders as a basis, the empirical analyses are based on various arguments from the voluntary disclosure theory as well as from principal-agency and related frameworks. In essence, most parts of the thesis follow the key assumption that bondholders demand higher premiums for opaqueness and potentially detrimental behavior on behalf of a bond issuer’s management. The analyses deliver new insights into the role of corporate disclosure and close a gap between bondholder relations and financial as well as shareholder-related disclosure. They contribute to the stream of research that is concerned with corporate disclosure and its relationship to the cost of capital, the cost of debt, and even more specifically the yield (spread) of corporate bonds.
Despite growing research on sustainability transformations, our understanding of how transformative transdisciplinary research can support local actors who foster change towards sustainability is still somewhat limited. To contribute to this research question, the investigator conducted research in a transdisciplinary case study in Southern Transylvania, where non-governmental organizations (NGO) drive sustainability initiatives to foster desired changes (e.g., supporting small-scale farmers or conserving natural and cultural heritage). Interactions with these local actors and reflections on the research question shaped the research of this dissertation. In paper 1, the author conducted a literature review on amplification processes that describe actions, which local actors can apply to increase the impact of their sustainability initiatives. In paper 2, he conducted a literature review on the application of indigenous and local knowledge (ILK) in sustainability transformations research to understand whether this research engages with the conceptualization of transformations from local actors. The results show that ILK is generally applied to confirm and complement scientific knowledge in contexts of environmental, climate, social-ecological, and species change. In paper 3, the author derived principles that provide guidance for how to integrate sustainability initiatives from local actors in transformative transdisciplinary research. Based on his transdisciplinary research with the NGOs in Southern Transylvania and by using systems and futures thinking as an approach for analysis, he derived three principles that provide guidance for the co-design of sustainability intervention strategies that build on, strengthen, and complement existing initiatives from local actors. In paper 4, the author explored empirically how to identify relevant local actors for collaborations that seek to intervene in specific characteristics of a system (e.g., parameters or design of a system). He applied a leverage points' perspective to analyse the social networks of the NGOs in Southern Transylvania that amplify the impact of their initiatives. This dissertation as a whole contributes insights to three recommendations of how transformative transdisciplinary research can support local actors fostering change towards sustainability: First, by conducting research that studies and supports local actors who increase the impact of their sustainability initiatives via amplification processes (Paper 1 and 4); Second, by engaging specifically with the initiatives, networks, and knowledge from local actors, who foster bottom-up, place-based transformations (Paper 1-4); Third, by identifying and collaborating with local actors that are relevant for strategic systems interventions that build on, strengthen, and complement existing initiatives (Paper 3-4).
Business Models for Sustainability Innovation: Conceptual Foundations and the Case of Solar Energy
(2013)
This dissertation deals with the relationships between the increasingly discussed business model notion, sustainability innovation, and the business case for sustainability concept. The main purpose of this research is to identify and define the so far insufficiently studied theoretical interrelations between these concepts. To this end, according theoretical foundations are developed and combined with empirical studies on selected aspects of the solar photovoltaic industry. This industry is particularly suitable for research on sustainability innovation and business models because of its increasing maturity paired with public policy and market dynamics that lead to a variety of business model-related managerial and entrepreneurial business case challenges. The overarching research question is: How can business models support the commercialisation of sustainability innovations and thus contribute to business cases for sustainability? A theoretical and conceptual foundation is developed based on a systematic literature review on the role of business models in the context of technological, organisational, and social sustainability innovation. Further, the importance of business model innovation is discussed and linked to sustainability strategies and the business case for sustainability concept. These theoretical foundations are applied in an in-depth case study on BP Solar, the former solar photovoltaic subsidiary of British Petroleum. Moreover, because supportive public policies and the availability of financial capital are known to be the most important preconditions for commercial success with innovations such as solar photovoltaic technologies, the solar studies include a comparative multiple-case study on the public policies of China, Germany, and the USA as well as a conjoint experiment to explore debt capital investors’ preferences for different types of photovoltaic projects and business models. As a result, the main contribution of this work is the business models for sustainability innovation (BMfSI) framework. This framework is based on the idea that the business model is an artificial and social construct that fulfils different functions resulting from social interaction and their deliberate construction. The BMfSI framework emphasises the so-called mediating function, i.e. the iterative alignment of business model elements with company-internal and external requirements as well as with the specific characteristics of environmentally and socially beneficial innovations. Against this backdrop, it becomes clear that practically-oriented knowledge based on BMfSI research might provide new and effective ways to support the achievement of corporate sustainability.
Crowdfunding is considered a promising instrument for transforming existing socio-technical regimes by financing radical innovations of such entrepreneurs. However, this potential has not yet been fully explored. Therefore, this dissertation addresses the overarching research question of how sustainable entrepreneurs can exploit the full potential of investment-based crowdfunding to develop from niche operators to actors in the socio-technical regime. Five journal articles and one book chapter are included in this PhD project, which use a wide range of quantitative methodologies. In the framework paper, the findings are conceptually evaluated on a meta-level by applying the multi-level perspective. The key insights can be assigned to four categories, including the financing and marketing function, the target group, and the project presentation. The analysis shows that investment-based crowdfunding is suitable to equally fund and market the business ideas of environmental entrepreneurs, since the quest for entering the mass market is highest for such ventures. In contrast, purely social entrepreneurs tend to conduct crowdfunding projects on a smaller scale and probably aim to stay in the niche. Nevertheless, profit-oriented social entrepreneurs are still encouraged to use investment-based crowdfunding for funding and marketing purposes. The prominent display of environmental effects (e.g. the amount of compensated greenhouse gases) and financial incentives (e.g. high interest rates) has a high impact on the investment decision of individuals on investment-based crowdfunding platforms. The case of fairafric is used as a best practice example to demonstrate how crowdfunding can be a stepping stone for sustainability-oriented niche actors to enter the mass market. The fair-trade and organic chocolate manufacturer has undergone six crowdfunding campaigns which enabled it to grow and build a strong community of supporters. The outcomes of this dissertation clarify how sustainable entrepreneurs can unleash the potential of investment-based crowdfunding for financing and marketing purposes.
This paper-based dissertation deals with capital structures and tax policies of German family businesses. Family firms as the predominant company form in Germany are mainly characterized by the overlapping of the two spheres family and business, both having different goal systems and preferences. This also has an impact on decision making with regard to corporate finance including the application of tax avoidance policies. In Germany, bank finance is the dominant financing source for family firms but there is a preference for internal finance since it comes along with more external independency. Extant research usually bases its results on samples of publicly listed companies. These studies come up with different results regarding family firms' actual financing preferences and capture their heterogeneity only to a very little extent. In this light, the present dissertation and its three papers examine different research questions in the context of capital structure decisions and tax avoidance in family firms. All the three papers apply a quantitative empirical research design. The first paper is a comparison between capital structures of family firms and non-family firms. The paper examines differences in bank debt and trade credit ratios. Overall, the findings show that family firms have significantly higher overall and long-term debt levels compared to their non-family counterparts. The identity as a family firm, which leads to a leap of faith by banks, can be a possible explanation for these results. The second paper is an in-depth examination of drivers of bank debt levels within the group of family firms. Further, it addresses heterogeneity amongst family firms and combines survey results and corresponding financial information. This represents a first attempt to capture family firm heterogeneity and its link to financial issues. The study shows that the more power in the company is exerted via management or supervisory board by the family, the less bank debt is used. Paper three is an extension of the previous two studies as it sheds light on tax avoidance, a significant instrument to strengthen the internal financing capability of a firm. This also takes up a research gap as there is very little research on taxation in family firms. Contrary to the expectation, the study reveals that private family firms might pay less tax than their non-family peers.
In this dissertation the relation between time headway in car following and the subjective experience of a driver was researched. Three experiments were conducted in a driving simulator. Time headways in a range of 0.5 to 4.0 seconds were investigated at 50km/h, 100km/h, and 150km/h under varied visibility conditions and at differing levels of driver control over the car. The main research questions addressed the possible existence of a threshold effect for the subjective experience of time headways and the influence of vehicle speed, forward visibility, and vehicle control on the position of time headway thresholds. Furthermore, the validity of zero-risk driver behavior models was investigated. Results suggest that a threshold exists for the subjective experience of time headways in car following. This implies that the subjective experience of time headways stays constant for a range of time headways above a critical threshold. The subjective experience of a driver is only influenced by time headway once this critical time headway threshold is passed. Speed does not influence preferred time headway distances in self- and assisted-driving, i.e. time headway thresholds are constant for different speeds. However, in completely automated driving preferred time headways are influenced by vehicle speed. For higher speeds preferred time headways decrease. A reduction of forward visibility leads to a shift in preferred time headways towards larger time headways. Results of this dissertation give credence to zero-risk models of driver behavior.
Does grass-roots civic engagement improve the quality of public services in countries in which formal oversight institutions are weak? It is obvious that formal oversight institutions are weak in developing countries, which causes low-quality public services. This weakness is particularly critical in the health sector - a service domain of crucial relevance for development. This observation has led practitioners to believe that the direct engagement of the beneficiaries of public services is a means to compensate the weakness of oversight institutions and to improve the quality of these services. Given that beneficiaries have incentives to demand good quality services, it is indeed logical to assume that their participation in the monitoring of public services helps to improve the quality of these very services. This positive view of grass-roots civic engagement resonates with the idea that an active civil society helps a political system to build up and sustain a high institutional performance In the eyes of the donors of development aid, this idea nurtures the expectation that strengthening civic engagement contributes to increased aid effectiveness. Accordingly, donor countries have increased their efforts to strengthen beneficiary participation since the 1990s, which moved the concepts of voice and accountability center-stage in the international development discourse. However, whether citizens' capacity to exercise pressure on service providers and public officials really improves the effectiveness of development aid remains an unresolved question. Building upon recent experimental and comparative case study evidence, the thesis examines the role of citizens' engagement in the effectiveness of development interventions. The focus is on such interventions in the health sector because population health is particularly critical for prosperity and development, and ultimately for democratization. The key question addressed is if and under what conditions ordinary people's engagement in collective action and their inclination to raise their voice improves the effectiveness of development assistance for health (DAH). I analyze this question from an interactionist viewpoint, unraveling the complex interplay of civic engagement and health aid with three key institutional variables: (i) state capacity, (ii) liberal democracy and (iii) decentralized government. Drawing upon social capital theory, principal-agent theory, and selectorate theory, I provide compelling evidence that health aid effectiveness depends on (a) bottom-up processes of demand from service users as well as (b) formal processes of top-down monitoring and horizontal oversight arrangements. In other words, the very interaction of behavioral and institutional factors drives the accountability in public service provision and thus the effectiveness of development assistance for health in recipient countries.
In this dissertation, a multi-proxy study, which included palaeoecological, lithological, geochemical and geochronological methods, was carried out to investigate climatic and environmental changes and their interaction during the Quaternary in formerly glaciated and non-glaciated areas. The information obtained will be used to provide a better understanding of the regional stratigraphic framework and to establish broader regional terrestrial correlations within the global marine isotope stage (MIS) framework. This study was conducted on two key drillings, the Garding-2 research drill core in the German North Sea coastal area of Schleswig-Holstein and the GBY#2 archaeological core at the Gesher Benot Ya'aqov (GBY) site, in the Upper Jordan Valley in Israel. The results of this study are presented in three papers. Papers I and II focus on the study of the Garding-2 core, while the multi-proxy study of the GBY#2 core is presented in Paper III. The results of a variety of analyses conducted on the 240 m long Garding-2 sequence show interglacial-glacial cycles that are mainly controlled by variations in temperature. This sequence is composed of mainly fluvial-shallow marine sediments intercalated by muddy-peaty deposits. Based on the palynological and lithological findings, the Pliocene-Pleistocene transition was observed at 182.87 m. It is overlain by Praetiglian and the subsequent sediments of the Waalian and Bavelian Complexes. The boundary of either the second or third Cromerian Interglacial with younger sediments, which still belong to MIS 19, is marked by the last occurrence of Tsuga at 119.50 m and the development of mixed-deciduous forests. The palynologically equivalent sediments of the Bilshausen Interglacial were found below two Elsterian till layers, at 89.00 m-82.00 m. These sediments showed high and increased percentages of Pinus and Picea and scattered occurrences of Abies and Carpinus, which are similar to the features of the beginning of the Bilshausen or Rhume interglacial. An unconformity occurred at 80.29 m, at the bottom of late Holsteinian deposits, characterised by the occurrences of Fagus and Pterocarya, with low percentages of Abies and Carpinus and the absence of Buxus. These deposits are succeeded by sediments of the Fuhne cold period that shows higher percentages of NAP and occurrences of Ericales, Helianthemum and Selaginella selaginoides, which are unconformably overlain by Drenthian till at 73.00 m-71.00 m. A single peaty sample at 69.25 m with Pinus-Picea-Abies assemblage is correlated with the late Eemian Interglacial. This deposit is overlain by Weichselian glaciofluvial sediments. Middle-late Holocene sediments occurred from 20 m upwards, following a hiatus, which was caused by the Early Holocene transgression. A subsequent thin layer of marine Atlantic sediments is unconformably overlain by marine-tidal flat deposits up to 11.00 m. The first occurrence of Fagus (at 15.97 m) and Carpinus (at 15.03 m), which was optically stimulated luminescence (OSL)-dated to 3130 +/- 260 BP (at 16.22 m, Zhang et al., 2014), gives evidence for a Subboreal age for these deposits. Sandy sediments of the early Subatlantic, which were deposited between 11.00 m and the top of the Garding-2 sequence, indicate that local salt marshes, dunes and tidal flat vegetation expanded during this period. Due to regional features and the peculiarities of the local coastal environment, the expansions of Fagus and Carpinus, which are characteristic for the Subboreal-Subatlantic transition at about 2700 BP in northern Germany, are not clearly reflected in the Garding-2 pollen diagram. In the Mediterranean area, a 50 m long core of GBY#2, was drilled at the Acheulian site of Gesher Benot Ya'akov. The GBY#2 core provides a long Early-Middle Pleistocene geological, environmental and climatological record, which also enriches the knowledge of hominin-habitat relationships documented at the margins of the Hula Palaeo-lake. The sediment sequence of GBY#2 is under- and overlain by two basalt flows that are 40Ar/39Ar dated: two samples at the bottom of the core dated to 1195 +/- 67 ka (at 48.30 m) and 1137 +/- 69 ka (at 45.30 m), and another one at the top dated to 659 +/- 85 ka (at 14.90 m). With the additional chronological identification of the Matuyama Brunhes Boundary (MBB) and the correlation with the GBY excavation sites, the sedimentary sequence of GBY#2 provides the climatic history during the late part of the mid-Pleistocene transition (MPT, 1.2 Ma-0.5 Ma). Multi-proxy analyses including those of pollen and non-pollen palynomorphs, macro botanical remains, molluscs, ostracods, fish, amphibians and micromammals provide evidence for lake and lake-margin environments during MIS 20 and MIS 19. During MIS 20, relatively cool semi-moist conditions were followed by a pronounced dry phase. During the subsequent MIS 19, warm and moist interglacial conditions were characterised by Quercus-Pistacia woodlands in this area. The depositional environment changed from an open water lake during MIS 20 to a lake margin environment in MIS 19. This finding is at odds with changing climate conditions from relatively dry to moist. This discrepancy could be explained by the prograding pattern of the lake shore due to the infilling of the basin, which resulted in shallower water. Climatic changes during the Late Tertiary and the Quaternary in the high latitude regions in northwest Europe and during the Early-Middle Pleistocene in the mid latitude regions of the Middle East follow the patterns of global climatic changes, which are mainly controlled by orbital obliquity (+/-41 ka cycle) during the Early Pleistocene and by orbital eccentricity (+/-100 ka cycle) during the MPT (1.2 Ma-0.5 Ma) and the younger periods of the Quaternary. The results of this study also provide reliable evidence for long distance correlation of stratigraphic and climatic events of the Quaternary, which extends knowledge of regional and global impact of climatic fluctuations on the environment.
Rangelands are the most widespread land-use systems in drylands, where they often represent the only sustainable form of land-use due to the limited water availability. The intensity of the land-use of such rangeland ecosystems in drylands depends to a large extent on the climatic variability in time and space. Rangeland systems are seriously threatened by climate change, because climate change will alternate the availability of water in time and space. This dissertation therefore deals with the question which role climatic variability plays for the effects of grazing on vegetation in dry rangelands. The relatively intact steppes in central Mongolia were chosen as a model system. They are characterised by low precipitation and high climatic variability in the south (100mm annual precipitation), and comparatively high precipitation and low climatic variability in the north (250mm). The effects of grazing on vegetation on 15 grazing transects were investigated along the climatic gradient. The central elements were the plant species and their abundances on 10m x 10m areas, for which functional characteristics such as height, affiliation of functional groups or leaf nutrients were recorded. The main hypothesis of this dissertation is that grazing has a greater impact on vegetation communities with increasing rainfall. To test this hypothesis, three studies were carried out. In a first study, the research group found that the vegetation communities in the dry area differ strongly along the climatic gradient, while the plant communities in the wetter area differ more strongly along the grazing gradient. The results of the second study suggested that this difference can be explained by a functional environmental filter that becomes weaker from south to north as the niche spectrum increases. The third study has shown that this is likely a function of the higher availability of resources, which at the same time leads to higher grazing pressure, therewith stressing the vegetation especially in years with droughts. In summary, the author concludes that the climate gradient also represents an environmental filter that filters species for certain characteristics, thus having a significant influence on the vegetation. Climatic variability influences the effect of grazing on vegetation, which is particularly problematic where the grazing intensity is high and the species are less adapted to strong climatic fluctuations. Future scenarios predict increasing productivity and therefore increasing livestock density. This may lead to an increase in floristic and functional diversity across the climate gradient, but also to increasing grazing effects and therefore threads for overgrazing. Increasing climatic variability is likely to intensify this thread, especially in the moister regions, whereas the dry rangelands are likely to be more resilient due to the adaptation of the plants to non-equilibrium dynamics.
The postal sector has a long monopolistic tradition in many countries; however, since the 1990s it has undergone considerable changes. At the beginning of that decade, the European Commission abolished exclusive rights within the postal system and opened up the market to new private postal providers and changes have continued to accelerate after two important European directives. Both directives were intended to improve the quality of service in the industry and to open up the market to competition. What has changed since the opening of the German postal market? A look at market shares measured by volumes of processed postal items, or by revenue, quickly reveals the prevailing dominance of the former monopolist Deutsche Post AG (DPAG). Despite an increasing number of market entries by private postal providers, it seems the German postal market is still characterized by the old monopolistic structures and that the aim of creating a competitive environment has not been fully achieved. This thesis deals with different competition issues from an economics perspective. The analyses are based on self-collected data and in-depth interviews conducted during on-site visits and thus provide first empirical evidence regarding the status quo in the German postal market.
The wide accessibility of the Internet and web-based programs enable an increased volume of online interventions for mental health treatment. In contrast to traditional face-to-face therapy, online treatment has the potential to overcome some of the barriers such as improved geographical accessibility, individual time planning, and reduced costs. The availability of clients' treatment data fuels research to analyze the collected data to obtain a better understanding of the relationship among symptoms in mental disorders and derive outcome and symptom predictions. This research leads to predictive models that can be integrated into the online treatment process to assist clinicians and clients. This dissertation discusses different aspects of the development of predictive modeling in online treatment: Categorization of predictive models, data analyses for predictive purposes, and model evaluation. Specifically, the categorization of predictive models and barriers against the uptake of mental health treatment are discussed in the first part of this dissertation. Data analysis and predictive modeling are emphasized in the second part by presenting methods for inference and prediction of mood as well as the prediction of treatment outcome and costs. Prediction of future and current mood can be beneficial in many aspects. Inference of users' mood levels based on unobtrusive measures or diary data can provide crucial information for intervention scheduling. Prediction of future mood can be used to assess clients' response to the treatment and expected treatment outcome. Prediction of the expected treatment costs and outcomes for different treatment types allows simultaneous optimization of these objectives and to increase the cost-effectiveness of the treatment. In the third part, a systematic predictive model evaluation incorporating simulation analyses is demonstrated and a method for model parameter estimation for computationally limited devices is presented. This dissertation aims to overcome the current challenges of predictive model development and its use in online treatment. The development of predictive models for varies data collected in online treatment is demonstrated and how these models can be applied in practice. The derived results contribute to computer science and mental health research with client individual data analysis, the development ofpredictive models, and their statistical evaluation.
Extracting meaningful representations of data is a fundamental problem in machine learning. Those representations can be viewed from two different perspectives. First, there is the representation of data in terms of the number of data points. Representative subsets that compactly summarize the data without superfluous redundancies help to reduce the data size. Those subsets allow for scaling existing learning algorithms up without approximating their solution. Second, there is the representation of every individual data point in terms of its dimensions. Often, not all dimensions carry meaningful information for the learning task, or the information is implicitly embedded in a low-dimensional subspace. A change of representation can also simplify important learning tasks such as density estimation and data generation. This thesis deals with the aforementioned views on data representation and contributes to them. The authors first focus on computing representative subsets for a matrix factorization technique called archetypal analysis and the setting of optimal experimental design. For these problems, they motivate and investigate the usability of the data boundary as a representative subset. The authors also present novel methods to efficiently compute the data boundary, even in kernel-induced feature spaces. Based on the coreset principle, they derive another representative subset for archetypal analysis, which provides additional theoretical guarantees on the approximation error. Empirical results confirm that all compact representations of data derived in this thesis perform significantly better than uniform subsets of data. In the second part of the thesis, the research group is concerned with efficient data representations for density estimation. The researchers analyze spatio-temporal problems, which arise, for example, in sports analytics, and demonstrate how to learn (contextual) probabilistic movement models of objects using trajectory data. Furthermore, they highlight issues of interpolating data in normalizing flows, a technique that changes the representation of data to follow a specific distribution. The authors show how to solve this issue and obtain more natural transitions on the example of image data.
Conflicts between intragenerational and intergenerational justice in the use of ecosystem services
(2012)
The principle of sustainability contains two objectives of justice regarding the conservation and use of ecosystems and their services: (1) global justice between different people of the present generation ("intragenerational justice"); (2) justice between people of different generations ("intergenerational justice"). International sustainability policy attaches equal normative importance to both objectives of justice. Accordingly, environmental philosophers ethically justify that people living today and people living in the future have equal rights to certain basic goods, including ecosystems and their services (e.g. Feinberg 1981, Visser’t Hooft 2007). Whereas ideal theories of sustainability and justice do not recognize interdependencies between intragenerational and intergenerational justice, conflicts in attaining the justices possibly arise in policy implementation. Identifying and preventing such conflicts is fundamental to devise an ethically legitimate, politically consistent and actually effective sustainability policy. This dissertation systematically investigates conflicts between intragenerational and intergenerational justice in the use of ecosystem services. Human wellbeing depends on the services provided by ecosystems. Yet, humans substantially degrade world’s ecosystems, and therewith cause the loss of important ecosystem services (MEA 2005: 26ff.). The idea of sustainability demands to use ecosystem services in accordance with the two objectives of intragenerational justice and intergenerational justice. Reality, however, is far from attaining these objectives: Both today’s global poor and future persons are, resp. will be, disproportionately affected by the loss of vital ecosystem services (MEA 2005: 62, 85). Especially severe affected are the rural poor who directly depend on local ecosystem services for food, income and health. The political discourse on the relationship between the objectives of intra- and intergenerational justice in the use of ecosystem services (‘justice-relationship’) is blurred. Further, the political discourse lacks a common understanding of justice in ecosystem-use and a systematic reflection on the actual ‘justice-relationship’, such as on the factors that cause conflicts between the two justices. In this dissertation, I investigate the ‘justice-relationship’ along three central questions: • What conception(s) of justice can adequately address the distribution of access rights to ecosystem services? • How must sustainability policy be designed to enhance both intragenerational and intergenerational justice in the use of ecosystem services? • (How) Can economics be helpful for characterizing and assessing trade-offs between the two justices? I approach these questions both generally and by the example of a case study, the MASIPAG farmer network in the Philippines. Methodologically, I combine a normative and a positive analysis of the relationship between intra- and intergenerational justice in the use of ecosystem services: The normative analysis serves the explication, justification and reflection of the norms underlying the ‘justice-relationship’; the positive analysis serves the description of the ‘justice-relationship’ in the sustainability discourse and in practical contexts, as well as the provision of explanations on the determinants of the ‘justice-relationship’. As methodological approach, I apply the “comprehensive multi-level approach” as developed by Baumgärtner et al. (2008) – investigating the ‘justice-relationship’ simultaneously on the three levels of (i) concept, (ii) model and (iii) case study.
Prospective students´ choice of their university is a topic of rising relevance worldwide. As competition on the higher education market and the resultant fight for students increases, universities need to deal with questions of how, when, and why young people decide where to study. This knowledge forms the basis for developing adequate and effective communication strategies enabling university marketers to recruit the best and most suitable students for their institutions. Despite extensive research on these questions, there still are fundamental gaps like the nonobservance of sense making activities, the neglected role of emotions and higher education policies, the suboptimal choice of research methods as well as problematic theoretical assumptions previous research is based upon. In this dissertation, I address all of these gaps in three complementary articles. In the first paper, I compare American with German research on university choice by focusing on the three aspects of theoretical approaches applied in previous studies, choice factors, and information sources prospective students use. On the basis of this literature review, I identify major research gaps with a focus on, but not limited to, the German context. In the second article, by using the Zaltman Metaphor Elicitation Technique (ZMET), I identify mental models of prospective students that represent their sense making activities. Through this, I get a profound understanding of which rational and especially emotional issues are relevant for the students when they try to make sense of the marketing messages they are confronted with during their university choice process. In the third paper, I challenge the theoretical approaches previous research is based upon by identifying two very different types of decision-makers with their respective choice strategies and logics. Overall, this dissertation contributes to a much more detailed understanding of prospective students´ university choices by identifying their sense-making activities and choice styles, highlighting the role of emotions and context factors, and refining the theoretical foundations university choice research is based upon.
Corporate irresponsibility is often the result of intentionally irresponsible strategies, decisions, or actions, which negatively affect an identifiable stakeholder or environment. For instance, these range from the violation of the human rights and labor standards to environmental damages. Organizations enacting irresponsible practices rely on different factors upon multiple levels (field, organizational, individual) and its interrelations as well as processes evolving within the organization leading to such behavior. However, reasons for the occurrence of and explanations for corporate irresponsibility so far have been limited, leaving a fragmented understanding of this phenomenon. This dissertation helps to improve the understanding and explanation of corporate irresponsibility by identifying driving patterns of corporate irresponsibility and showing how the interactions across multiple levels add to this phenomenon. Chapter 1 provides an overview of the topic of corporate irresponsibility, the theoretical approaches of this dissertation and an introduction to the chapters. The second chapter offers a review and analysis of the corporate irresponsibility literature. The chapter presents a variance model outlining the concept, antecedents, moderators and outcomes of recent corporate irresponsibility literature as well as the different factors across levels (field, organizational, individual). Chapter 2 offers a critical analysis of what we know by referring to current literature and offers insights on what we don't know by deriving main implications for future research on corporate irresponsibility. Chapter 3 enlarges the understanding of corporate irresponsibility introducing a process approach to explain how corporate irresponsibility evolves over time and under which conditions. Based on a qualitative meta-analysis findings converge around two distinct process paths of corporate irresponsibility, the opportunistic-proactive, and, the emerging-reactive, subdivided into three phases. Chapter 3 sheds different lights upon the phases of corporate irresponsibility and its underlying mechanisms. The final chapter 4 focuses on different underlying mechanisms driving the final downfall or demise of organizations, organizational failure. Chapter 4 offers an alternative explanation to the competing extremism and inertia mechanisms driving organizational failure in recent studies by suggesting that these explanations are rather complementary. In addition, chapter 4 enlarges the explanation of organizational failure identifying the role of conflict mechanisms and its interplay with rigidity mechanisms. In sum, this dissertation contributes to a better understanding of what causes and increases corporate irresponsibility, and a better explanation of how and why corporate irresponsibility and organizational failure emerges, develops, grows or terminates over time.
Companies are invited to contribute to the United Nations' 17 Sustainable Development Goals (SDGs) and sustainability management accounting (SMA) has an important role to play in achieving them. However, if companies are to address the SDGs and linkages beyond organizational boundaries, SMA needs a broader scope than is conventionally assumed. Therefore, the author advances a multi-level framework that addresses context, action-formation, and transformative contributions (CAT) in the following directions: first, an innovative systematic method that allows screening company-related SDGs and assessing corporate contributions to selected SDGs is introduced; second, management control systems are integrated to support managers in guiding employee behavior to make contributions to the SDGs; and, third, self-reinforcing mechanisms of the path-dependence theory are incorporated to serve as a guide to identifying barriers to individuals and groups becoming involved in SMA. This advanced CAT framework contributes to corporate practice and research by providing a multilevel framework that offers concrete management guidance for SMA to address the SDGs. It also facilitates analysis of both enabling and inhibiting factors at the organizational level. The advanced CAT framework has several implications for SMA: it promotes backcasting from the SDGs for benchmarking purposes, integrates different social, environmental, and economic issues, facilitates future-oriented action and transformation planning, addresses different layers such as the company as well as individuals and groups within it and enables to identify barriers hindering individuals and groups from becoming involved in SMA.
This cumulative dissertation presents how commercial banks in Germany communicate their ambitions and commitment regarding corporate responsibility - i.e., CSR. The results of the first article show that the quality of mandatory non-financial reporting needs to be improved and that certain characteristics (e.g., previous reporting experience, reporting format and standard) have a positive influence on reporting quality. The second article shows that the CSR reporting scope on bank websites also has room for improvement and that various banking characteristics such as size, capital market orientation, media visibility or public ownership have an influence on communication. The third article illustrates that credit institutions in Germany are increasingly using social media for CSR communication, but that CSR communication strategies differ (Facebook vs. Twitter). The fourth article discusses CSR communication using advertisements and shows that the conceptual design of advertisements should be in line with the credit institution's business model and is therefore beneficial.
Corruption as “the abuse of entrusted power for private gain” (Transparency International, 2013) is detrimental to economic, social and political development. It intensively violates the fundamental principles of democracy such as equality, fairness, transparency and accountability (Sandholtz and Taagepera, 2005). Europe exhibits a wide spectrum of corrupt activities and is characterized by large differences as to the extent and dynamics of corruption. Thus, it is astonishing that there is still little knowledge about the region-specific factors that determine corruption. Considering corruption as a multilevel phenomenon that takes place at the country level and is often measured by certain aggregated indices, this project examines corruption also at the individual level with data from the World Values Survey. The study includes 37 European countries at the macro level and 20 countries at the micro level (1995-2010). For comparative purposes and in order to uncover specific European determinants of corruption, all statistical calculations are run with an additional sample (“non-European country sample”), including countries world-wide. The results of the panel and multilevel analysis indicate that a country’s rate of inflation, international integration, the degree and duration of democracy, anti-corruption policy, the percentage of women in parliaments, religion, society’s history of corruption strongly influence the extent and dynamics of corruption at the country-level. At the individual level, an individual’s employment status, satisfaction with the financial situation, emancipative values, interpersonal trust and the justification of bribery are significant causes of corruption across and within European countries. A comparison of these results with the findings of the “world sample” clearly demonstrates that there are regional differences.
This thesis aims to provide a quantitative, cross-nationally comparative, longitudinal and multilevel study of the drivers and hindrances of national governments' anti-trafficking measures. In this research, both macro-level determinants of anti-trafficking enforcement and micro-level foundations of human trafficking are explored. In the manuscript, large-N comparative research examines how characteristics of countries interact with people's attitudes towards violence to better understand what creates environments that are more or less supportive of governments' anti-trafficking efforts. The results presented in the thesis speak not only in favor of studying this topic systematically and cross-nationally, addressing existing gaps in the literature but also in favor of combining macro- and micro-level evidence for developing more effective policy responses against human trafficking.
Against the background of the dependence of cultural institutions on public funding and the increasing pressure on public budgets, this thesis aims to make a contribution to the economic analysis of the German cultural sector. For this purpose, three empirical studies focusing on the German cultural sector are conducted, using different methods to quantify the analyzed effects. Chapter 2 describes an application of the contingent valuation method (CVM) for assessing public approval of the amount of subsidies spent on cultural facilities. For our analysis, we conducted a contingent valuation study to capture the willingness to pay (WTP) for the municipal cultural supply in Lüneburg, Germany. To identify the factors associated with the respondents’ WTP, we supplemented an ordinary least squares (OLS) and a Tobit regression model with a quantile regression (QR) model. The findings suggest the existence of non-use values. Since the QR analyzes the coefficients at different points of the distribution of the dependent variable, it accounts for the heterogeneity of preferences. Overall, the results indicate that the QR can provide useful information in deriving implications for cultural policy. In contrast to the consumption-oriented approach of chapter 2, chapters 3 and 4 focus on the production of performing arts in public theaters. Data were taken from the theater reports published by the German Stage Association (Deutscher Bühnenverein) from 1993 to 2007. Chapter 3 uses a stochastic frontier analysis approach to analyze the efficiency of German public theaters. Whether the assumption of cost-minimizing behavior is reliable in the case of public theaters is of particular interest. Thus, in addition to the input distance function model, we employ a cost function model in order to evaluate whether the cost-minimizing behavior can be maintained. We also applied several panel data models that differ in their ability to account for unobserved heterogeneity to evaluate the impact of unobserved heterogeneity on the efficiency estimates. The results indicate that the cost-minimizing assumption cannot be maintained. We also find a considerable unobserved heterogeneity across the theaters that causes a significant variation in the models’ efficiency estimates. Taken together, our results suggest that there is still space for improvement in the employment of resources in the area of performing arts production in Germany. The third study, presented in Chapter 4, discusses the development and sources of productivity in German public theaters. As labor costs increase, productivity decreases over time; this phenomenon is referred to as ”Baumol’s cost-disease”. However, productivity is not influenced only by technological change; technical efficiency and scale efficiency also play a role. Thus, which of the three factors are positive or negative drivers for productivity change in the case of German public theaters is of particular interest. Using a stochastic distance frontier approach to decompose the total factor productivity into the three different sources of productivity the findings indicate that there is no significant technological progress that can countervail the negative productivity trend caused by increasing wages and, thus, support the cost-disease hypothesis. Furthermore, increasing returns to scale for the majority of theatres were found. Chapter 5 summarizes the main results of the three empirical analyses. This is followed by concluding remarks on the need for further research.
Fostering socio-economic development throughout all Member States is a fundamental goal of the European Union. With one third of its budget, the EU tries to support regional development in lessdeveloped regions and improve the life of its citizens. To reach its goal, a shift can be observed from a single sided focus on factor mobility and thus transportation and other infrastructure facilities to a higher diversity in approaches, including culture, the arts and creativity. Here, creative industries and innovation are keywords within Structural Funds, the main instrument of EU regional policies. However, very little is known on how cultural operators in the form of artists, opera houses etc. contribute to regional development by implementing Structural Funds projects. The framework conditions set on EU level are very open, allowing the sector to contribute in their own way to socioeconomic development. To improve the understanding of how cultural operators access Structural Funds this dissertation was guided by the question: What kind of strategies do cultural operators use to access Structural Funds in Poland? Or on a more abstract level: What are the formal and informal norms within the application process for cultural operators, and in which way do they impact the application strategies of cultural operators in Poland? By working on those questions, this dissertation is providing an insight into how cultural operators on the ground approach Structural Funds. The case study on cultural operators in Poland serves as a concrete example and gives a clearer picture of access strategies, barriers and facilitators within this process. Because research is scarce on this subject, a choice for an in-depth case study analysis within one country was taken. With a theoretical framework of sociological Neo Institutionalism, especially a model developed by Victor Nee and Paul Ingram (1998), the research focusses on different levels of interaction and the role of formal and informal norms. The model was modified to support the analysis of actors’ strategies, and explain the application process of cultural operators. Here, the focus was on the micro level (cultural operators) and its interaction with the meso level (national). The model was enriched at the end of the research with elements of Bourdieu’s theory of practise, namely his concepts of fields and capital. Poland was selected as case study country due to its unique position as the biggest new Member State with its long cultural tradition at the heart of Europe and a very positive formal framework for cultural projects within Structural Funds. The focus was on the years 2004-2007 and thus covered mainly the first funding period for Poland. As empirical evidence, 27 expert interviews were carried out with cultural operators and their environment in Poland. They were analysed on a qualitative basis, using Atlas.ti, and co-occurrence network views. The author conducted all interviews within a period of two months, and most of the interviews were conducted in English. Important steps within the analysis were the emergence of a project idea, the ‘melting’ of this idea into a project application, different challenges linked to the application process and information gathering as a crucial factor within this process. In the end, the findings were validated by three EU experts from the Commission and the European Parliament. Conclusions: Findings show that the application strategy is driven by a set of formal and informal norms. Among them one can find elements linked to financing and co-financing, access and distribution of information and capacity building in the form of knowledge gathering and experience. The informal channels proved to be especially valuable. Further, the organisation resources have a significant impact when applying for Structural Funds. This is not limited to sufficient financial means but also related to existing networks and knowledge of whom to ask for information and support. Here, reference can be made e.g. to Bourdieu’s concept of capitals. Based on those findings, a typology of three different actors’ groups with different challenges and project profiles was developed. It can be shown that their positions and strategies are influenced, not only by formal rules and norms, but also to a high level, by informal norms and structures. As a result, projects were generally implemented by rather big and well-established organisations. Most of them focussed on the conservation of cultural heritage or the construction of new, ‘classical’ cultural infrastructure such as museums and opera houses. However, innovation and creativity are thought to grow especially in smaller, often younger and ‘different’ settings. As the EU is interested in those elements to find a region-tailored solution to socio-economic development needs, a nearly exclusive focus on rather traditional flagship projects implemented by well-established organisations appears insufficient: In other words, there is a discrepancy between proclaimed possibilities and attempts within political statements and Structural Funds rules on one side and the picture on the ground on the other side. Thus, if the fostering of socio-economic development through innovation and new approaches is to emerge, attempts need to be taken to increasingly support cultural operators with less favourable given capital. The thesis presented enhances knowledge within these processes and therefore contributes to the improvement of the situation. Because only if conditions are analysed and known, processes on national and EU level can change and alternatives be considered. As a conclusion for the micro level, a strong networking and gathering of know-how independently from formal structures seems the most promising short-term approach. From a long-term perspective, a formalisation of networks and stronger lobbying, especially on national level but also on EU level will be needed if framework conditions are to change in favour of a more diversified and flexible approach.
During recent decades, the arenas of political decision-making have increasingly shifted from national governments to intergovernmental and transnational political forums. At the same time, the number and relevance of non-state actors in international politics is steadily growing. These trends have led political scientists to study and theorize about new forms of democracy beyond the national political arenas (Archibugi 2004, Bexell et al. 2010, Nasström 2010). However, democracy beyond the nation state is difficult to conceptualize with the idea of an institutionalized democracy within the borders of nation-states. Instead, many political scientists emphasize the role of civil society actors as a cure for the democratic deficit in inter-national politics (Steffek & Nanz 2008). Yet, normative and empirical problems arise over the extent of access, selection and role of civil society actors in international organizations (Tallberg et al. 2013). Furthermore, the normative relevance of transnational civil society actors makes it necessary to study their own democratic legitimacy. While international organizations are mostly institutionalized and hierarchical governing bodies, the ever growing diffuse conglomerate of non-state actors is characterized by fluid structures, blurry boundaries and a multi-level setting of interaction (Keck & Sikkink 1998). Thus, in studying democratic practice in transnational civil society networks, we must ask: How institutionalized do political practices have to be and how flexible can they be, to still be considered democratic? Normative theorists reconceptualized democracy in the light of this changing context (Bohman 2007). Recent concepts of participatory, deliberative and representative democracy attempt to reconfigure existing democratic institutions through procedural elements (Fung & Wright 2003, Dryzek 2006) or innovative forms of representation (Phillips 1998, Mansbridge 2003, Castiglione & Warren 2006). This emerging theoretical framework is well suited to analyze the extent, to which democratic practices exist within transnational civil society networks. By applying the concept of practice (Giddens 1984, Schatzki et al. 2005) as a bridging tool between the empirical reality of fluid, temporary and open transnational civil society networks on the one hand and the institution-oriented democratic theory on the other hand, this study explores the extent to which democratic practice develops in a field that lacks traditional institutions to guarantee citizen participation. As innovative transnational actors, civil society networks can bring up new forms of democratic practice (see Polletta 2006) that can potentially inspire the debate about transnational democracy as such. This study, with its innovate approach, hopes to invigorate the debate about transnational democracy and transnational civil society, which has stalled to some degree in recent years. The study is divided into three parts; first, a conceptual part that clarifies the question of how democracy as practice can be theoretically conceptualized in transnational civil society net-works, which is followed by an empirical exploration of political practices in the transnational civil society networks. In this second part, the main question is how participation, representation and deliberation practice develops in transnational civil society networks. Two cases of transnational civil society networks, the Clean Clothes Campaign and Friends of the Earth, are analyzed to provide insights into the democratic practice within transnational civil society. In the final part, the empirical findings are evaluated in the light of the outlined concepts of democratic theory in order to explore how democratic these political practices actually are. The study identifies implicit and in-process practices of democratic norms in transnational civil society networks. Political practice in transnational civil society networks can become demo-cratic through empowerment measures and trustful relationships. However, deliberate demo-cratic practice can be impeded by disembodied digital communication and complex decision-making. The study explores how new forms of democratic practice emerge in the interaction between political actors and the structural environments of actors and networks.
Design methods for collaborative knowledge production in inter- and transdisciplinary research
(2022)
This dissertation seeks to better understand how design methods facilitate collaborative knowledge production and integration in inter- and transdisciplinary sustainability research. Through five independent papers, this dissertation contributes to addressing the research question on four levels – conceptual-epistemological, empirical, methodological and practical. By exploring the linkages between design research and inter- and transdisciplinary research, a conceptual basis for the targeted use of design methods in collaborative processes of inter- and transdisciplinary research is laid and their spectrum of methods is expanded. This is followed by the development of a transformative epistemology in and for problem-oriented, collaborative forms of research, such as transdisciplinary sustainability research, called problematic designing. Based on a deeper understanding of integration and collaborative knowledge production, as well as its accompanying challenges, empirical research into applying design prototyping as a method in and for situations of collaborative research was conducted. To this end, the findings provide a fundamental basis for the facilitation of inter- and transdisciplinary research processes when dealing with complex problems. With its inherent openness and iterative approach in addressing the unknowns of complex phenomena, design prototyping contributes to the required form of imagination that enables to anticipate possible futures. Furthermore, by including visual-haptic modes of expression, design prototyping reduces the dominance of language and text in scientific negotiation processes and does justice to the diversity of cognitive modes. Finally, the empirical findings of this dissertation emphasise the importance of the visual-haptic dimension for collaborative knowledge production and the communication of knowledge, and provide insights into the visual structuring of human thought processes. The results on material metaphors, collaborative prototyping and material-metaphorical imagery contribute decisively to the basic knowledge of the epistemological quality of design and the importance of the visual and haptic for thought processes in general. The extension and adaptation of existing analysis methods in this dissertation add to the further development of analysis of visual-haptic data. The results are once again reflected in the synthesis of this framework paper as cross-cutting issues.
The energy sector is regarded as one of the decisive subsystems influencing the future of sustainable development. Consequently, there is a need for a comprehensive transformation of energy generation, conversion and use. The importance of building capacities for energy policy development in developing countries is bound up with the need to formulate global strategies to meet the challenges that humanity face, especially to achieve the targets manifested in the Agenda 2030 and Paris Agreement. The aim of this research is to better understand how to empower marginalised key societal actors, co-produce alternative discourses about energy futures and articulate those discourses to influence policy change within a context of illiberal democracies in Latin America. The research concerns the design, function and effectiveness of scientifically grounded participatory process, which has been justified theoretically and tested empirically. The process presupposes theoretical perspectives relating to theory, method and empirical application. The first draws on theories of sustainability transition and transformation, including transition management. The second draws on ideas taken from the knowledge co-production and transdisciplinary sustainability research. The empirical application, concerns the implementation of a Transdisciplinary Transition Management Arena (TTMA) and its effectiveness, measured by potential for the co-production of knowledge and for stimulating collective action. As result of the process, a conceptual model of the energy system, long-term visions and transformation strategies were developed. The TTMA processes demonstrated that cross-sectoral and inter-institutional, combined efforts, can help actors visualize possible, future alternatives for sustainable energy development and how to realize such alternatives. The structures provided were helpful for the emergence and empowerment of new sustainable-energy-transition coalitions in both Ecuador and Peru. Chapter 1 describes the general context in which this scientific project is developed and presents a synthesis of the processes and its main outcomes. The research results are described in detail in the scientific papers presented in chapters 2, 3 and 4.
Detecting and Assessing Road Damages for Autonomous Driving Utilizing Conventional Vehicle Sensors
(2021)
Environmental perception is one of the biggest challenges in autonomous driving to move inside complex traffic situations properly. Perceiving the road's condition is necessary to calculate the drivable space; in manual driving, this is realized by the human visual cortex. Enabling the vehicle to detect road conditions is a critical and complex task from many perspectives. The complexity lies on the one hand in the development of tools for detecting damage, ideally using sensors already installed in the vehicle, and on the other hand, in integrating detected damages into the autonomous driving task and thus into the subsystems of autonomous driving. High-Definition Feature Maps, for instance, should be prepared for mapping road damages, which includes online and in-vehicle implementation. Furthermore, the motion planning system should react based on the detected damages to increase driving comfort and safety actively. Road damage detection is essential, especially in areas with poor infrastructure, and should be integrated as early as possible to enable even less developed countries to reap the benefits of autonomous driving systems. Besides the application in autonomous driving, an up-to-date solution on assessing road conditions is likewise desirable for the infrastructure planning of municipalities and federal states to make optimal use of the limited resources available for maintaining infrastructure quality. Addressing the challenges mentioned above, the research approach of this work is pragmatic and problem-solving. In designing technical solutions for road damage detection, the researchers conduct applied research methods in engineering, including modeling, prototyping, and field studies. They utilize design science research to integrate road damages in an end-to-end concept for autonomous driving while drawing on previous knowledge, the application domain requirements, and expert workshops. This thesis provides various contributions to theory and practice. The investigators design two individual solutions to assess road conditions with existing vehicle sensor technology. The first solution is based on calculating the quarter-vehicle model utilizing the vehicle level sensor and an acceleration sensor. The novel model-based calculation measures the road elevation under the tires, enabling common vehicles to assess road conditions with standard hardware. The second solution utilizes images from front-facing vehicle cameras to detect road damages with deep neural networks. Despite other research in this area, the algorithms are designed to be applicable on edge devices in autonomous vehicles with limited computational resources while still delivering cutting-edge performance. In addition, the analyses of deep learning tools and the introduction of new data into training provide valuable opportunities for researchers in other application areas to develop deep learning algorithms to optimize detection performance and runtime. Besides detecting road damages, the authors provide novel algorithms for classifying the severity of road damages to deliver additional information for improved motion planning. Alongside the technical solutions, they address the lack of an end-to-end solution for road damages in autonomous driving by providing a concept that starts from data generation and ends with servicing the vehicle motion planning. This includes solutions for detecting road damages, assessing their severity, aggregating the data in the vehicle and a cloud platform, and making the data available via that platform to other vehicles. Fundamental limitations in this dissertation are due to boundaries in modeling. The pragmatic approach simplifies reality, which always distorts the degree of truth in the result.
The dissertation contains four journal articles which are embedded within a framework manuscript that interconnects the individual articles and provides relevant background information. The dissertation's overall objective is to provide a multilayered and critical in-depth engagement with the timely phenomenon of integrated reporting (IR), a new reporting concept that is envisaged to revolutionize firms' present reporting infrastructure. While extant corporate reports (e.g., annual financial- and CSR report) often are criticized for being disconnected and to suffer from a lack of coherence, IR intends to provide all information that is material to a firm's short-, medium- und long-term value creation within one single, succinct document. To contribute to a set of previously defined relevant research gaps in literature, the dissertation makes use of a combined empirical-quantitative and explorative-qualitative research design. The first article entitled investigates a set of different IR-, corporate governance and financial accounting-specific factors that are expected to determine European and South African firms' materiality disclosure quality. To this purpose, an original, hand-collected materiality disclosure score was developed. The second article explores IR perceptions of SME managers that have not embarked on IR, but are potential candidates to do so in future. Based on a review of extant literature, the article develops a theoretical framework to subsequently discuss motives for and barriers to IR adoption. The critical discussion contributes to the academic debate on incentives for and barriers to voluntary IR adoption. The third article investigates whether voluntary IR adoption among European firms is associated with lower cost of public debt. While earlier studies suggest that IR leads to lower information asymmetries, increases analyst forecasts, and decreases cost of equity, corresponding evidence for the debt market is largely missing. Subsequent analyses test as to whether such an association is even more pronounced by a firm's environmental, social and governance (ESG) performance or its belonging to an environmentally sensitive industry. The fourth article uses an experimental design to investigate nonprofessional investors' reactions to an IR assurance. To this purpose, two separate experiments with two different groups of nonprofessional investors were carried out: one with Masters students and one with managers of large corporations. Results help to answer the question as to whether an IR assurance as well as its determinants, namely the assurance provider and the assurance level, affect nonprofessional investors' financial decision-making. In the second step, subsequent in-depth interviews reveal an IR assurance-critical attitude among managers, who draw upon their practical experience with assurance engagements.
Determinants of Emotional Experiences in Traffic Situations and Their Impact on Driving Behaviour
(2013)
Emotions play a prominent role in explaining maladaptive driving and resulting motor vehicle accidents (MVAs). Above all, traffic psychologists have focussed their attention on anger and anxiety, including the origins and influence of these emotions on driving behaviours. This dissertation contributes to the field with three manuscripts that build upon each other. Those manuscripts have three separate objectives. The first identifies the broad range of emotions in traffic that should be analysed. Second, the impact of specific emotions on driving behaviour is focussed. Finally, the research investigates how situational and personal factors can influence emotional experiences and influence driving behaviour. The first article tackles the bandwidth of emotions in traffic. In two consecutive online studies (study one: = 100; study two: n = 187), different emotional experiences were assessed using the Geneva Emotion Wheel (and an advanced version). The stimulus material consisted of written traffic situations structured around specific factors (in these studies, predominantly goal congruence, goal relevance and blame). It could be shown that the properties of the situation can elicit emotions such as anger, anxiety and happiness, but also pride, guilt and shame. The second article saw a transfer of those situational factor structures from online-presented text to simulated driving. At this time, the focus of interest was the driving behaviour influenced by the elicited emotions. The simulator study (n = 79) revealed that anger, contempt and anxiety led to similar declines in driving performance profiles. Performance declines included driving at higher speeds, more frequent speeding and worse lateral control. The third article examined to what extent anger and personal characteristics could negatively influence driving behaviour. Two studies were conducted (study one: n = 74; study two; n = 80). The results indicated that specific characteristics of the person (male, little driving experience, high driving motivation, high trait-driving anger) could influence driving behaviour in negative ways, both directly and indirectly, via triggered anger emotions. It can be concluded from these results that the range of emotions in traffic encompasses much more than just anger and anxiety. Furthermore, the second and third articles show that within simulated environments, minimal but effective emotional intensities can be triggered, and those emotions (especially anger and anxiety) create similar performance patterns. Personal characteristics should be considered when explaining the elicitations of emotion and subsequent driving behaviour. The papers of this dissertation echo the call for new comprehensive models to explain the relationships among emotions and traffic behaviours.
It is understood among research and policy makers that addressing unsustainable individual consumption patterns is key for the vision of sustainable development. Education for Sustainable Consumption (ESC) is attributed a pivotal role for this purpose, aiming to improve the capacity of individuals to connect to and act upon knowledge, values and skills in order to respond successfully and purposefully to the demands of sustainable consumption. Yet despite political, scientific, and educational efforts and increasing awareness in the general population, little has been achieved to substantially change behavioral patterns so far. As part of the explanation for this shortcoming, it has been argued that current ESC practices have neglected the personal dimension of sustainable consumption, especially the affective-motivational processes underlying unsustainable consumption patterns. Against this background, this cumulative thesis is guided by the question how personal competencies for sustainable consumption can be defined, observed, and developed within educational settings. Special attention is given to mindfulness practices, describing the practice of cultivating a deliberate, unbiased and openhearted awareness of perceptible experience in the present moment. Drawing upon an explorative, qualitative research methodology, the thesis looks at three different mindfulness-based interventions aiming to stimulate competencies for sustainable consumption, reaching out to a total number of 321 participants (employees and university students). In this thesis, the author suggests to define personal competencies for sustainable consumption as abilities, proficiencies, or skills related to inner states and processes that can be considered necessary or sufficient to engage with sustainable consumption (SC). These include ethics, self-awareness, emotional resilience, selfcare, access to and cultivation of personal resources, access to and cultivation of ethical qualities, and mindsets for sustainability. The thesis holds that the observation of personal competencies benefits from a combination of different methodological and methodical angles. When working with self-reports as empirical data, a pluralistic qualitative methods approach can help overcoming shortcomings that are specifically related to individual methods while increasing the self-reflexivity of the research. Moreover, it is suggested to let learners analyze their own personal statements in groups, applying scientific methods. The products of the group analyses represent data based on an inter-subjectively shared perspective of learners that goes beyond self-estimation of personal competencies. In terms of developing personal competencies for SC, it can be concluded that mindfulness practice alone is not sufficient to build personal competencies for SC. While it can stimulate generic personal competencies, individuals do not necessarily apply these competencies within the domain of their consumption. Nevertheless, mindfulness practice can play an important role in ESC, insofar as it lays the inner foundation to engage with sustainability-related issues. More precisely, it allows learners to experience the relevance of their inner states and processes and the influence they have on actual behaviors, leading to a level of selfawareness that would not be accessible solely through discursive-intellectual means. Furthermore, participants experience mindfulness practice as a way to develop ethical qualities and access psychological resources, entailing stronger emotional resilience and improved well-being. In order to unleash its full potential for stimulating personal competencies for SC, however, the findings of the thesis suggest that mindfulness practice should be (a) complemented with methodically controlled self-inquiry and (b) related to a specific behavioral change. In this vein, self-inquiry-based and self-experience-based learning – two pedagogical approaches developed during the period of research for this thesis – turned out to be promising pedagogies for educational settings striving to stimulate the development of personal competencies for SC.
Food forests present a promising solution to address multiple sustainability challenges adaptable to local contexts. As biodiverse multi-strata agroforestry systems, they can provide several ecological, socio-cultural and economic services. They sequester carbon, limit soil erosion and regulate the micro-climate; they offer the opportunity for education on healthy diets and ecology, and they produce food and can create livelihood opportunities. However, despite their obvious benefits, food forests are still a niche concept. To date, research has focused on their ecological and social services; we lack an understanding of food forests as a comprehensive sustainability solution, including their economic dimension, and knowledge on how to develop them. Addressing these gaps, this qualitative research used a solution- and process-oriented methodology guided by transformational sustainability research. In a comparative case study approach, it created an inventory of 209 food forests, followed by interviews and site visits of 14 sites to understand their characteristics and assess their sustainability (Article 1). More indepth, it analyzed the implementation path of seven food forest for success factors, barriers and coping strategies (Article 2). Based on these insights, two experimental case studies were initiated to develop sustainable food forests with practice partners, one based in Phoenix, Arizona, U.S. and one in Lüneburg, Germany. Two studies analyzed the cases' outputs and processes highlighting success factors and challenges, including the role of a sustainable entrepreneurial ecosystem (Article 3, Phoenix case) and key features of productive partnerships to understand why one case succeeded and the other failed (Article 4). Findings include key features of existing and sustainable food forests as well as success factors on how to develop them; namely acquiring a complementary skill set that includes specialty farming and entrepreneurial know-how, securing sufficient start-up funds and long-term land access as well as overcoming regulatory restrictions. Supporting institutions are especially needed to integrate and professionalize the planning stage and provide know-how on alternative business practices. Key features of productive partnerships include an entrepreneurial attitude, access to support functions, long-term orientation and commitment to food system sustainability.
Thermal energy storage systems have a high potential for a sustainable energy management. Low temperature thermochemical energy stores based on gas-solid reactions represent appealing alternative options to sensible and latent storage technologies, in particular for heating and cooling purposes. They convert heat energy provided from renewable energy and waste heat sources into chemical energy and can effectively contribute to load balancing and CO2 mitigation. At present, several obstacles are associated with the implementation in full-scale reactors. Notably, the mass and heat transfer must be optimized. Limitations in the heat transport and diffusions resistances are mainly related to physical stability issues, adsorption/desorption hysteresis and volume expansion and can impact the reversibility of gas-solid reactions. The aim of this thesis was to examine the energy storage and cooling efficiency of CaCl2, MgCl2, and their physical salt mixtures as adsorbents paired with water, ethanol and methanol as adsorbates for utilization in a closed, low level energy store. Two-component composite adsorbents were engineered using a representative set of different host matrices (activated carbon, binderless zeolite NaX, expanded natural graphite, expanded vermiculite, natural clinoptiolite, and silica gel). The energetic characteristics and sorption behavior of the parent salts and modified thermochemical materials were analyzed employing TGA/DSC, TG-MS, Raman spectroscopy, and XRD. Successive discharging/charging cycles were conducted to determine the cycle stability of the storage materials. The overall performance was strongly dependent on the material combination. Increase in the partial pressure of the adsorbate accelerated the overall adsorbate uptake. From energetic perspectives the CaCl2-H2O system exhibited higher energy storage densities than the CaCl2 and MgCl2 alcoholates studied. The latter were prone to irreversible decomposition. Ethyl chloride formation was observed for MgCl2 at room and elevated temperatures. TG-MS measurements confirmed the evolution of alkyl chloride from MgCl2 ethanolates and methanolates upon heating. However, CaCl2 and its ethanolates and methanolates proved reversible and cyclable in the temperature range between 25°C and 500°C. All composite adsorbents achieved intermediate energy storage densities between the salt and the matrix. The use of carbonaceous matrices had a heat and mass transfer promoting effect on the reaction system CaCl2-H2O. Expanded graphite affected only moderately the adsorption/desorption of methanol onto CaCl2. CaCl2 dispersed inside zeolite 13X showed excellent adsorption kinetics towards ethanol. However, main drawback of the molecular sieve used as supporting structure was the apparent high charging temperature. Despite variations in the reactivity over thermal cycling caused by structural deterioration, composite adsorbents based on CaCl2 have a good potential as thermochemical energy storage materials for heating and cooling applications. Further research is required so that the storage media tested can meet all necessary technical requirements.
Panic disorder is a common anxiety disorder, which is associated with high subjective burden as well as a high cost for the health economy. According to the National Treatment Guideline S3, cognitive behavior therapy is recommended as the most effective psychological treatment. However, many people in need do not have access to cognitive behavior therapy. Internet-based interventions have proven to be an effective way to provide access to evidence-based treatment to those affected. For anxiety disorders, such as panic disorder and agoraphobia, a good effectiveness of internet-based interventions has been proven in numerous international studies. However, the internet has changed over the last few years: mobile technologies have considerable potential to further improve the adherence and effectiveness of internet-based interventions. Against this background, the authors developed the hybrid online training "GET.ON Panic". In this training, an app has been integrated into a browser-based online training. The app consists of a mobile diary for self-monitoring as well as a mobile exposure-guide that supports participants in self-exposure exercises in their everyday lives.In an initial exploratory feasibility study, qualitative interview data and quantitative measurements were collected in a pre-post design of 10 participants. Usage, user friendliness, user satisfaction and acceptance of the app were generally considered high. The use of interoceptive exposure exercises and daily summaries of anxiety and mood were the most widely performed and rated the best, while in vivo exposure exercises and the monitoring of acute panic symptoms were found to be difficult.In the efficacy study, 92 participants with mild to moderate panic symptoms were randomized into two parallel groups. After eight weeks, the intervention group showed a significant improvement in the severity of panic symptoms compared to the waiting control group. Using the intention-to-treat approach, a covariance analysis with baseline values as a covariate yielded a mean effect of Cohen's d=0.66 in reducing the panic symptoms in favor of the intervention group. This effect increased to d=0.89 after three months and stayed at d=0.81 at the 6-month measurement point. Response and remission rates were also significantly higher in the intervention group. This positive effect was also shown for secondary outcomes such as depressive symptoms and quality of life. A correlation between app usage and clinical outcomes could not be found. This work was the first to demonstrate that a hybrid online training based on cognitive behavior therapy is effective in reducing panic symptoms as well as panic disorder. In addition, this work contributes to a deeper understanding of the potential of mobile technologies in the field of e-mental health.
Air quality models are important tools which are utilized for a large field of application. When combined with data from observations, models can be employed to create a comprehensive estimation of the past and current distribution of pollutants in the atmosphere. Moreover, projections of future concentration changes due to changing emissions serve as an important decision basis for policymakers. For the determination of atmospheric concentrations of air pollutants by means of numerical modelling it is essential to possess a model which is able to create anthropogenic and biogenic emissions with a temporally and spatially high resolution. The emission data is needed as input for a chemistry transport model which calculates transport, deposition, and degradation of air pollutants. To evaluate the impact of changing emissions on the environment a flexible emission model with the capability to create diverse emission scenarios is needed. Further, it is important to always take into account a variety of different species to properly represent the major chemical reactions in the atmosphere (e.g. ozone chemistry, aerosol formation). Currently there are only a few high resolution emission datasets available for Europe. The amount of substances included in these datasets, however, is limited. Moreover, they can not be used as basis for the creation of new emission scenarios. To enable the creation of emission scenarios in the course of this doctoral thesis the American emission model SMOKE was adopted and modified. On the basis of a multitude of different georeferenced datasets, official statistics, and further model results the newly created emission model “SMOKE for Europe” is capable of creating hourly emission data for the European continent with a spatial resolution of up to 5x5km2. In order to demonstrate the universal applicability of the emission model the carcinogenic species benzo[a]pyrene (BaP) was exemplarily implemented into the model. BaP belongs to the group of polycyclic aromatic hydrocarbons. Because of its high toxicity the European Union introduced an annual target value of 1 ng/m3 in January 2010. SMOKE for Europe was used to create a variety of emission scenarios for the years 1980, 2000, and 2020. These emission scenarios were then used to determine the impact of emission changes on atmospheric concentrations of BaP and to identify regions which exceed the European target value. Additionally the impact of different legislation and fuel use scenarios on the projected atmospheric concentrations in 2020 was investigated. Furthermore, additional use cases for a flexible emission model are pointed out. The SMOKE for Europe model was used to simulate the transport of volcanic ash after the eruption of the Icelandic volcano Eyjafjallajokull in March 2010. By comparison of modelled concentrations for different emission scenarios with observations from remote sensing and air plane flights distribution and concentration of the volcanic ash over Europe was estimated. The results of this thesis have been presented in four scientific papers published in international peerreviewed journals. The papers are reprinted at the end of this thesis.
The research described in this dissertation focuses on developing a process to remove oligomers and suppress their formation by intercepting the aging procedure's precursors using adsorbents when biodiesel and its blends are used as fuel. So far, there has been no attempt to cause the stabilization of biodiesel and its blends using adsorbents from open literature. This investigation is one of the first studies on the use of adsorbents to mitigate biodiesel and diesel fuel's stability behavior–biodiesel blends and the removal of oligomers or suppressing the formation of high molecular mass species in aging oil. This study's primary aim has been achieved by several experimental measurements that provided results on adsorbents' effecton fuel oxidative stability, especially ester-based fuel like biodiesel and its blends. The chemical composition and some critical rheological analyses of the samples have been measured to understand their role in the oxidation of the sample by comparing the presence and absence of the adsorbents during the aging process. Furthermore, it aims to use adsorbents to suppress oligomers' formation and remove them in aging oil due to the influence of biodiesel and its blends. The research project also seeks to stabilize fuel, especially ester-based fuel like biodiesel, and its blends using the adsorbents. The adsorbents' application will enhance biodiesel's oxidative stability and its blends during long-term storage or application, focusing on its use in plug-in hybrid vehicles, emergency power plants,and generators. The combustion engine only starts in plug-in hybrid vehicles if the battery cannot supply energy on longer journeys. As a result, the fuel remains longer in plug-in hybrid vehicles. Fuels that are exposed to heat and oxygen over anextendedperiod can form aging products. These aging products lead to the formation of deposits, especially in the case of diesel fuels mixed with biodiesel content,and can, therefore, endanger the operational safety of the vehicle in critical components such as injectors or filter units.
This thesis gives an overview on the diversity of some beetle species in different Mediterranean habitats as well as on the influence of forest management on insect diversity. Primarily, this work involved fundamental research, because very little research had previously been conducted under biodiversity aspects on either ground beetles or saproxylic beetles in the Mediterranean area of Israel. It was possible to prove that stenotopic ground beetles occur in different habitat types. Furthermore, the results of Chapter I and Chapter III show that additional research is needed to obtain a clear view of the beetle diversity in this area. Future studies should consider that a variety of catching methods are needed throughout the annual cycle in order to catch a good spectrum of ground beetles living in these habitats. It is clearly not sufficient to conduct a study of ground beetles using only pitfall traps and/or to restrict the study to the wet winter months. The conclusions and management recommendations are therefore as follows: More studies on insect biodiversity are needed to obtain a comprehensive overview of insects in natural and planted Mediterranean woodlands. To facilitate this for a wide spectrum of scientists, identification keys for the Mediterranean insect fauna are urgently needed. Furthermore, foresters are in a position to decide which tree species composition has to be established and for what purpose. Nowadays, issues of forest management are primarily led by the objectives and potential uses of the forests. In times of global change, however, the potential future climatic situation and the ecosystem services provided by different woodlands also have to be considered when planning forest management (cf. also DUFOUR-DROR 2005 for Israel). Forest management is therefore also a matter of regional development and must thus include social demands and conservation actions. In a recent paper, OSEM et al. (2008) propose that forest management should consider different objectives, e.g. forests as a provider of ecosystem services, such as water infiltration, carbon sequestration and biodiversity. For these reasons, foresters should take the opportunity to establish oak individuals as a woody understorey component in pine stands. This would not only increase forest diversity but also strengthen the forests’ resistance and resilience to pest outbreaks, and would ensure better ecosystem functioning and soil stabilisation (cf. GINSBERG 2006; OSEM et al. 2008; PAUSAS et al., 2004). Moreover, both old and recent woodlands provide unique sections of biodiversity, as revealed by the occurrence of species restricted to specific microhabitats. However, not only forest management but the management of all natural or semi-natural habitats in northern Israel is important. Many, if not all of these habitats, have been severely affected or completely destroyed by urban, industrial and agricultural development and fragmentation or by dense afforestation with non-native trees (e.g. Eucalyptus). This development, especially the loss of open space, is continuing because of Israel’s high human population density. For these reasons, all natural or semi-natural habitats are endangered (YOM-TOV & MENDELSSOHN 2004). This alarming development is in contrast with the overall importance of the region as a biodiversity hotspot (YOM-TOV and TCHERNOV 1988). This thesis demonstrates that there are numerous (also stenotopic) beetle species with preferences to specific habitats of open space (e.g. old-growth oak woodlands, recent oak woodlands, pine plantations, batha and old oak tree individuals). If Israel’s beetle diversity is to be preserved in future, it will be vital to protect all habitats and their succession stages.
Both practitioners and researchers alike assign considerable importance to innovation. However, the process of how innovation unfolds over time is still not well understood. It is the aim of this dissertation to introduce an elaborated picture of innovation processes over time and to discuss the implications of the dynamics of the innovation process for individuals working in innovative contexts, that is, leaders and team members of innovative teams. The first paper of lays the theoretical and empirical groundwork of my dissertation in demonstrating that within the boundaries of the gradual development of innovation activities over time innovation processes are recursive and highly dynamic. These dynamics make the innovation process a challenge for everyone involved in it. In the second and third paper of my dissertation, I discuss this challenge in greater detail for leaders and team members of innovative work teams. Thus, with this dissertation I do not only to give a more elaborate picture of how innovation projects unfold over time, but also describe the challenges attached to the innovation process and give first answers to the question of how individuals involved in this process may be able to master these challenges.
In addition to a short introduction, this thesis contains five chapters that discuss various topics in the context of labor economics in general and the manufacturing sector in Egypt in particular. Chapter one presents the institutional framework of the Egyptian labor market and the different datasets that could be used by researchers and summarizes some previous empirical studies. Then, different microeconometric methods are applied in the subsequent four chapters, using the World Bank firm-level data for the manufacturing sector in Egypt to get an empirical evidence for the following issues: determinants of using fixed-term contracts in the Egyptian labor market in the manufacturing sector in chapter two, determinants of female employment in Egyptian manufacturing firms in chapter three, ownership structure and productivity in the Egyptian manufacturing firms in chapter four and, finally, exporting behavior of the Egyptian manufacturing firms is analyzed with a special focus on the impact of workforce skills-intensity in chapter five.
In my dissertation I explore conceptual and economic aspects of resilience, i.e. a system’s ability to maintain its basic functions and controls under disturbances. I provide methodological considerations on the conceptual level and general insights derived from stylized ecological-economic models. In doing so, I demonstrate how to frame resilience so as to economically evaluate and investigate it as an important property of ecological-economic systems. Is conceptual vagueness an asset or a liability? In chapter 1 I address this question by weighing arguments from philosophy of science and applying them to the concept of resilience. I first sketch the wide spectrum of resilience concepts that ranges from concise concepts to the vague perspective of “resilience thinking”. Subsequently, I set out the methodological arguments in favor and against conceptual vagueness. While traditional philosophy of science emphasizes precision and conceptual clarity as precondition for empirical science, alternative views highlight vagueness as fuel for creative and pragmatic problem-solving. Reviewing this discussion, I argue that a trade-off between vagueness and precision exists, which is to be solved differently depending on the research context. In some contexts research benefits from conceptual vagueness while in others it depends on precision. Assessing the specific example of “resilience thinking” in detail, I propose a restructuring of the conceptual framework which explicitly distinguishes descriptive and normative knowledge. Chapter 2 investigates the common assumption that the optimization problem within a simple selfprotection problem (spp) is convex. It is shown that the condition given in the literature to legitimate this assumption may have implausible consequences. Via a simple functional specification we analyze the (non-)convexity of the spp more thoroughly and find that for reasonable parameter values strict convexity may not be justified. In particular, we demonstrate numerically that full self-protection is often optimal. Neglecting these boundary solutions and analyzing only the comparative statics of interior maxima may entail misleading policy implications such as underinvestment in self-protection. Thus, we highlight the relevance of full self-protection as a policy option even for non-extreme losses. Chapter 3 starts from the observation that ecosystem resilience is often interpreted as insurance: by decreasing the probability of future drops in the provision of ecosystem services, resilience insures risk-averse ecosystem users against potential welfare losses. Using a general and stringent definition of “insurance” and a simple ecological-economic model, we derive the economic insurance value of ecosystem resilience and study how it depends on ecosystem properties, economic context, and the ecosystem user’s risk preferences. We show that (i) the insurance value of resilience is negative (positive) for low (high) levels of resilience, (ii) it increases with the level of resilience, and (iii) it is one additive component of the total economic value of resilience. Chapter 4 performs a model analysis to study the origins of limited resilience in coupled ecologicaleconomic systems. We demonstrate that under open access to ecosystems for profit-maximizing harvesting forms, the resilience properties of the system are essentially determined by consumer preferences for ecosystem services. In particular, we show that complementarity and relative importance of ecosystem services in consumption may significantly decrease the resilience of (almost) any given state of the system. We conclude that the role of consumer preferences and management institutions is not just to facilitate adaptation to, or transformation of, some natural dynamics of ecosystems. Rather, consumer preferences and management institutions are themselves important determinants of the fundamental dynamic characteristics of coupled ecological-economic systems, such as limited resilience. Chapter 5 describes how real option techniques and resilience thinking can be integrated to better understand and inform decision making around environmental risks within complex systems. Resilience thinking offers a promising framework for framing environmental risks posed through the non-linear responses of complex systems to natural and human-induced disturbance pressures. Real options techniques offer the potential to directly model such systems including consideration of the prospect that the passage of time opens new options while closing others. Examples are provided which illustrate the potential for integrated resilience and real options approaches to contribute to understanding and managing environmental risk.
Biodiversity loss could jeopardize ecosystem functioning. Yet, the evidences that support this demonstration have been mostly obtained in aquatic and grassland ecosystems. Howbiodiversity affects ecosystem functioning still remain largely unanswered in forests, particularly in subtropical broad-leaved evergreen forests (EBLF). Tree productivity, among a wealth of forest ecosystem functioning, is of particular interest because it reflects the carbon sink capacity and wood productivity. Biodiversity-productivity relationships have been usually investigated at community level. However, tree-tree interactions occur at small scale. Thus, local neighborhood approach may allow a better understanding of tree-tree interactions and their contributions to the effects of biodiversity on tree productivity / growth rates. This thesis aims to analyze the effects of biodiversity and the abiotic environmental factors on the tree growth rates using both local neighborhood and community-based approaches. Furthermore, tree growth rates vary among different tree species. Functional traits have been related to the species-specific growth rates to understand the effects of species identity. Therefore, I also evaluated the crown- and leaf traits to predict the interspecific difference in growth rates. For a better understanding of the mechanisms that underline the relationships of biodiversity and tree growth rates, data of high solution and along time series is required to scrutinize the tree-tree interactions. Thereupon, I evaluated the applicability of terrestrial laser scanning (TLS) in assessing the tree dendrometrics. This thesis was conducted in the Biodiversity Ecosystem Functioning (BEF)–China experiment, which is located in a mountainous subtropical region in southeast China. A total of 40 native broad-leaved tree species were planted. In the first study, I used the local neighborhood approach to analyze how local abiotic conditions (i.e. topographic and edaphic conditions) and local neighborhood (i.e. species diversity and competition by neighborhood) affect the annual growth rates of 6723 individual trees. The second study used the community approach to partition the effects of environmental factors (i.e. topographic and edaphic), functional diversity according to Rao’s quadratic entropy (FDQ) and community weight mean (CWM) of 41 functional traits on community tree growth rates. The main question of the third study was how the species-specific growth rates are related to five crown- and 12 leaf traits.
In the fourth study, I investigated 438 tree individuals for the congruence between the conventional direct field measurements and TLS measurements. It was found that tree growth rates were strongly influenced by the local topographic and edaphic conditions but not affected by the diversity of local neighborhood. In contrast, results obtained by using the community-based approach showed that FDQ and CWMs of various leaf traits rather than abiotic environmental factors had significant impact on the community means of growth rates. Tree-tree interactions already occur in early life stages of trees, which were evidenced by the significant effect of competition by local neighborhood. These findings imply that the effects of abiotic environmental factors may be more evident at local scale and biodiversity effects may vary at different spatial scales. The species-specific growth rates were found to be related to specific leaf traits but not to crown traits and were best explained by both types of traits in combination. This finding supports the niche theory and provides the evidence for using functional diversity to examine the BEF relationships. The TLS-retrieved total tree height, stem diameter at 5 cm above ground, and length and height of the longest branch were highly congruent with those obtained from direct measurements. It indicates that TLS is a promising tool for high resolution, non-destructive analyses of tree structures in young tree plantations. Being one of very few studies to incorporate the individual tree scale in examining the biodiversity-productivity relationships within the BEF researches, this thesis stresses the importance of using individual-tree based approach, functional diversity and TLS to find the evidences of explanatory mechanisms of the observed biodiversity and ecosystem functioning (e.g. tree growth rates) relationships. Biodiversity effects may evolve along the successional stages. Therefore, incorporating the interaction between biodiversity and time in analyzing BEF relationship is also encouraged.
This dissertation evaluated the efficacy of three different internet-based interventions that can be regarded as indirect interventions to reduce depression since they primarily targeted risk factors for depression. For this purpose three registered randomized controlled trials were conducted. In addition to assessing the efficacy of the interventions regarding the primary outcomes, the efficacy to reduce depression and further secondary outcomes was studied. In Study I (N=200) the efficacy of an internet-based stress management intervention (iSMI), which was adapted and tailored to career starting teachers, was compared to a waitlist control group (WLG). The participants of the intervention group (IG) reported significant reductions on the primary outcome perceived stress at post-intervention (T2) and three month follow-up (3-MFU). Furthermore, it was shown that the intervention indirectly also reduced depression at T2 and 3-MFU. The effects were sustained at an extended 6-MFU. Besides efficacy, the feasibility to complement the iSMI with a newly developed internet-based classroom management training was shown. Moreover, mediation analyses corroborated the role of problem- and emotion-focused coping skills in the intervention's effect on stress and the indirect effect of the intervention on depression through stress. Study II (N=262) demonstrated the efficacy of an internet- and app-based gratitude intervention on the reduction of primary assessed repetitive negative thoughts at T2 and 3-MFU, as compared to a WLG. The participants of the IG also reported significantly reduced depressive symptoms at T2, and 3-MFU, with significant clinically meaningful effects. The effects were sustained at an extended 6-MFU. Besides efficacy, mediation analyses showed that repetitive negative thinking mediated the gratitude intervention's effect on depression. Finally, Study III N(=351) showed that an internet-based intervention, tackling worries at the beginning of the COVID-19 pandemic, was effective as compared to an active mental health advice group. At T2, two weeks after randomization, the IG reported significantly reduced levels on the primary outcome worry as compared to controls. Participants of the IG also reported significantly reduced levels of depression at T2, with significant clinically meaningful reductions. The extended follow-ups in the IG indicated that the improvements from baseline were sustained until the 2-MFU and the 6-MFU. In a mediation analysis, worry was shown to mediate the intervention's effect on depression. Across all three studies a reliable deterioration of depression was occasionally observed. In summary, the studies in this dissertation demonstrated the efficacy of various indirect interventions focusing on rather common psychological problems to indirectly reduce depressive symptoms. The extent to which depression severity could be reduced is comparable to reductions found within participants with comparable baseline depression severity, in internet-based interventions directly addressing depressive symptoms. Indirect interventions are suggested to increase the uptake of interventions that reduce depressive symptoms, since they might be perceived as less stigmatizing and might broaden the range of interventions to choose from.
Since 2000, data generation has been growing rapidly from various sources, such as Internet usage, mobile devices and industrial sensors in manufacturing. As of 2011, these sources were responsible for a 1.4-fold annual data growth. This development influences practice and science equally and led to different notations, one of the most popular one is Big Data. Besides organization with a business model based solely on Big Data, companies have started to implement new technologies, methodologies and processes in order to deal with the influx of data from different sources and structures and benefit the most of it. As the progress of the implementation and the degree of professionalism regarding data analysis differs amongst industries and companies, latter ones are faced with a lack of orientation regarding their own stage of development and existing relevant capabilities in order to deal with the influx of data as only a few best practices exist. Therefore, this research project develops a maturity model for the assessment of companies capabilities in the field of data analysis with a focus on Big Data. Basis for the model development is a construction model, developed along the criteria of Design Science Research. The developed model contains the different levels of maturity and related measurements for the evaluation of a companies Big Data capabilities with a focus on topics along the dimensions data and organization. The developed model has been evaluated based an application to different companies in order to ensure the practical relevance. The structure of the thesis is the following: In a first step, a structured literature review is carried out, focussing on existing maturity models in the field of Big Data and nearby fields as Business Intelligence and Performance Management Systems. Based on the identified white spots, a design science research oriented construction model for the maturity model development is designed. This model is applied subsequently.
Human activities have become a major driver of global change, so that global society and economy are facing consequences such as climate change, increasing scarcity of resources, environmental pollution and degradation as well as disturbances of ecosystem functioning and services.In order to meet these main challenges in an appropriate way, adequate starting points and solutions must be pursued at all levels to shift the current socio-economic pathway from an unsustainable to a safe operating and thus sustainable development within the planetary boundaries. One of the application concepts in industrial contexts is Industrial Symbiosis (IS), which deals with the set-up of advanced circular/cascading systems, in which the energy and material flows are prolonged for multiple material and energetic (re-)utilization within industrial systems in order to increase resource productivity and efficiency, while reducing environmental impacts. The overarching goal of the research project was to identify and develop approaches to enable the evolution of Industrial Symbiosis (IS) in Industrial Parks (IPs). IS is a collaborative cross-sectoral approach to connect the resource supply and demand of various industries in order to optimize the resource use through exchange of materials, energy, water and human resources across different companies, while generating ecological, technical, social and economic benefits. Many Information Communication Technology (ICT) tools have been developed to facilitate IS, but they predominantly focus on the as-is analysis of the IS system, and do not consider the development of a common desired target vision or corresponding possible future scenarios as well as conceivable transformation paths from the actual to the defined (sustainability) target state. This gap shall be addressed in this work, presenting the software requirements engineering results for a holistic IT-supported IS tool covering system analysis, transformation simulation and goal-setting. This study also aims to present the conceptual IT-supported IS tool and its corresponding prototype, developed for the identification of IS opportunities in IPs. This IS tool serves as an IS facilitating platform, providing transparency among market players and proposing potential cooperation partners according to selectable criteria (e.g. geographical radius, material properties, material quality, purchase quantity, delivery period). Therefore a quantitative indicator system was compiled and recurring patterns were identified to utilize this knowledge in the comprehensive IT-supported IS tool. So this IS tool builds the technology-enabled environment for the processes of first screening of IS possibilities and initiation for further complex business-driven negotiations and agreements for long-term IS business relationships.
This dissertation deals with the investigation of success factors in the field of entrepreneurship, especially entrepreneurship training, from a psychological perspective. In particular, I argue that the identification of certain psychological aspects helps to better understand the underlying mechanisms for successful entrepreneurship trainings and thus, enables successful entrepreneurship. In the second chapter I theoretically examined planning as a fundamental action an entrepreneur hast to undertake in order to succeed. Scholars are in disagreement about the question if planning is crucial for the entrepreneurship. Thus, I provide a comprehensive overview of the advantages and disadvantages of planning in entrepreneurship from a psychological perspective. I explain negative aspects (e.g., lack of knowledge, difficulty to predict the future, and inflexibility) as well as positive aspects (e.g., legitimating, action-regulatory, and learning function) about planning in entrepreneurship. Furthermore, I develop a theoretical model that combines both the positive and negative aspects of planning in entrepreneurship. With this theoretical model, I integrate different types of planning (e.g., formal and informal plans) as well as positive and negative functions of planning (e.g., learning or stickiness, inflexibility) to provide a first approximation for a theory of entrepreneurial planning. In the third chapter, to focus on the field of entrepreneurial trainings, I empirically examine the under-researched field of the relation between trainer and trainee. I use the transformational leadership theory (Bass, 1985) and a theory of learning outcome (Kraiger, Ford, & Salas, 1993), to hypothesize that the trainers´ charisma has a positive effect on the trainees´ entrepreneurial self-efficacy. Additionally, I search for possible moderators for the hypothesized trainer-trainee-relationship in an explorative manner, using insight from different research areas (e.g., pedagogy, philosophy). To test the hypotheses, I conducted a 12-week entrepreneurship training by which I had 12 measurement waves across four classes with 161 students and 12 trainers, which lead to 919 observations. In the fourth chapter, to broaden the perspective on the mechanisms within entrepreneurship training, which lead to a successful outcome, I empirically examined the short- and long-term effects of entrepreneurship training on life satisfaction. To do so, I developed a theoretical model based on theories of life satisfaction, that explain the underlying mechanisms of the short- and long-term effects of the entrepreneurship training on life satisfaction. With this model I hypothesize, that entrepreneurship training has a positive short- effect on life satisfaction, which is mediated through entrepreneurial self-efficacy. I furthermore hypothesize, that the long-term effect of the entrepreneurship training is mediated through self-employment. The short term-effect acts like a boost and vanishes over time, whereas the long-term effect holds in the long run. To test these hypotheses, I conducted entrepreneurship training as part of a randomized controlled field experiment with five measurement waves over a total period of 2.5 years. Using discontinuous growth modeling to take into account the temporality of our hypothesized effects we statistically analyzed the 1,092 observations from 312 students. Chapter 5 concludes this dissertation with general discussion of the three chapters.
Entrepreneurship is an important means for economic development and poverty alleviation . Due to the relevance of entrepreneurship, scholars call for research that contributes to the understanding of successful business creation. In order to best understand new venture creation, research needs to investigate barriers of entrepreneurship. A barrier that has received wide attention in the literature on new venture creation is capital requirements. Scholars argue that capital requirements are an entry barrier for new venture creation, as most people who start businesses have difficulties in acquiring the necessary amount of capital needed for starting the businesses. Particularly in developing countries, scholars and practitioners regard improvements in access to capital as a major solution to support new venture creation. However, besides improving access to capital, there are alternative solutions that help to deal with the problems of capital requirements and capital constraints in the process of new venture creation. In this dissertation, I argue that a possible means to master capital requirements and capital constraints in business creation is action-oriented entrepreneurship training. I draw on actionregulation theory (Frese & Zapf, 1994), theories supporting an interactionist approach (Endler & Edwards, 1986; Terborg, 1981) and on theories about career development (Arthur, 1994; Briscoe & Hall, 2006) to reason that action-oriented entrepreneurship training allows for handling capital requirements and capital constraints with regard to business creation. Specifically, I argue that action-oriented entrepreneurship training helps to deal with financial requirements and capital constraints in two ways: First, the training reduces the negative effect of capital constraints on business creation through the development of financial mental models. Second, the training supports finding employment and receiving employment income, which enable businesses creation.
This study aims to answer four main research questions regarding the roles, strategies, barriers, and representation of the media and environmental nongovernmental organisations (ENGOs) in environmental communication in Malaysia. From a theoretical lens, this study has incorporated the essential concepts of media, ENGOs, and environmental communication from both Western and Asian, particularly Malaysian perspectives as primary points of reference. For the purpose of this study, a total of 13 interviewees from Media A and Media B and 11 interviewees from ENGO A and ENGO B were chosen for the qualitative interview while 2,050 environmental articles were collected as samples from Media A´s and Media B´s newspapers along with ENGO A´s and ENGO B´s newsletters from the period 2012 to 2014 for the quantitative content analysis. Specifically, the findings from interview confirmed that both the Malaysian media and ENGOs have shared quite similar roles in environmental communication, particularly in environmental legitimacy (creating trust, credibility, and relationships with the public), in democracy (acting as a watchdog and mobilising the public sphere), and in constructing public mind about environmental problems. Pictures undoubtedly were one of the most vital tools in social construction, especially for presenting the reality of the environmental problems to the public. This was in harmony with the results of the quantitative content analysis, where more than 60% of pictures were found on environmental articles in media newspapers and ENGOs newsletters. Malaysian media and ENGOs have shared two common strategies in environmental communication, namely campaigning and collaboration with other stakeholders, while the ENGOs have two extra strategies: advocacy and lobbying strategies. Malaysian media and ENGOs also have collaborated with each other and the level of collaboration between them was at the coordination (medium) level. Both social actors especially the media were also relied heavily on their sources for environmental articles and the result of quantitative content analysis showed that the government was the main source for media newspapers, whereas other ENGOs and laypersons were the main sources for ENGOs´ newsletters. There are also colossal barriers faced by both Malaysian media and ENGOs throughout the process of environmental communication and some of the barriers faced by both media and ENGOs include the problem with limited knowledge of the environment, while some other barriers, like media laws and ownership, were only faced by the media; other barriers such as funding problems were specifically faced by the ENGOs. In terms of representation of environmental information, the Malaysian media make more presentations on environmental problems, especially on topics like floods, wildlife and water crises in their newspapers, while ENGOs have given more attention to environmental effort topics such as conservation and sustainable living in their newsletters. Surprisingly, not only the media but also the ENGOs used the same (news) values like timeliness, proximity, and impact as criteria for the selection of environmental issues for their publications. Other factors such as the background of the organisation and the interest of journalists or editors also influence the selection of environmental issues. It is hoped that the proposed theoretical framework of this study can serve as a crucial guideline for the development of environmental communication studies, especially among the media and ENGOs not only in Malaysia but also in other (Southeast) Asian regions that share a similar background.
In the discourse on pharmaceuticals in the environment, hardly any attention has been paid to anticancer drugs. Because of their none-selective modes of action, that is, because they affect both cancerous and healthy cells, these drugs are regarded as potentially carcinogenic, genotoxic, mutagenic, and teratogenic substances. It is, however, not known how and to what extent these substances affect organisms and the environment in the long run. For this reason, this dissertation evaluated, addressing several endpoints and using organisms from different trophic levels and in silico predictions, the fate (bio- and photo degradation) and ecotoxicity of these substances. Four anticancer drugs (cyclophosphamide (CP), 5-fluorouracil (5-FU), methotrexate (MTX), and imatinib (IM) were selected. None of these anticancer compounds can be classified as ´readily biodegradable,´ a classification that indicates that biodegradation will only play a minor role in the elimination of these compounds and that they cannot be removed by the conventional processes used in sewage treatment plants and will most likely remain in the water cycle. Despite the high degrees of mineralization achieved in advanced (photo)oxidation processes, it was not possible to fully mineralize the compounds, a result that indicates that transformation products were created during these reactions. The ecotoxicity assays performed with V. fischeri indicated that 5-FU was, of all the substances tested, likely to be the most toxic (very toxic), followed by MTX (toxic) and IM (toxic/harmful), whereas CP was nontoxic. MTX presented the highest phytoxicity activity in the Lactuca sativa assay, followed by 5-FU, IM, and CP. The results of the tests performed with A. cepa showed cytotoxic (5-FU, MTX, and CP) and genotoxic effects (5-FU, CP, and IM) and mutagenic activity (5-FU, MTX, CP, and IM) of the compounds. Photo transformation products (PTPs) of CP, MTX, and 5-FU were nontoxic towards V. fischeri. However, some PTPs formed during the photodegradation of 5-FU led to positive mutagenic and genotoxic alerts in several in silico models. Not one of the compounds examined in this dissertation is likely to be fully eliminated from the water cycle by (natural) photolysis and/or advanced oxidation. Moreover, some of the treatments resulted in the formation of stable intermediates that were even less biodegradable than parent compounds. This finding shows that it is not enough to focus on primary elimination because TPs are not necessarily better biodegradable than their respective parent compounds. As indicated by the genotoxic and mutagenic positive alerts presented by different in silico models, the PTPs observed here are likely to require, despite their lower toxicity in comparison to the parent compounds, screening after treatments.
Environmental governance beyond borders: Governing telecoupled systems towards sustainability
(2023)
This doctoral dissertation analyses the environmental governance of long-distance social-ecological interactions in telecoupled systems in two issue domains: global commodity chains and infrastructure projects as part of China’s Belt and Road Initiative (BRI). Although both domains involve different governance actors, institutions and processes, they both concern the question of how the involved actors develop governance structures and institutional responses to telecoupling. This dissertation aims to contribute to a deeper understanding of how to govern environmental problems that are associated with global flows. Since many multilateral environmental governance initiatives have not yet produced the desired solutions to global problems, particular attention is directed at unilateral state-led governance approaches. This dissertation addresses the questions of (1) how to achieve a spatial fit between the scale of telecoupled systems and the scale of governance institutions, (2) how governance actors exercise agency in governing telecoupled systems, and (3) how state actors can govern the domestic and foreign environmental effects of telecoupled flows. The results show that creating a spatial fit in the governance of global commodity flows is challenging because boundary and resolution mismatches can emerge. Boundary mismatches denote situations where social-ecological problems transcend established jurisdictional boundaries, whereas resolution mismatches refer to governance institutions that have too coarse a spatial resolution to allow them to address the specific aspects of social-ecological problems effectively. No single governance institution is likely to avoid all mismatches, which highlights the need to align multiple governance approaches to effectively govern telecoupled systems.
The fact that digitalization comes along with a lot of negative effects onto the environment is slightly known in the case of energy consumption by hardware, especially regarding mobile devices, having a limited battery life. However, awareness of environmental issues of software, being the driver of hardware, is mainly missing, even if the research field addressing corresponding issues is growing. Thus, the doctoral thesis at hand addresses the question How to draw (a) developers and (b) usersattention to environmental issues of software? By presenting (a) a calculation method of the carbon footprint of software projects and (b) a concept for an eco-label for software products, evaluated by a user survey, the doctoral thesis provides two strategies how to draw the attention to environmental issues of software. Summarizing, this thesis can act as a basis for further research in bridging from science to society in the context of environmental issues of software. Its findings can be seen as starting points for practical implementations of methods and tools supporting a more environmentally friendly way of developing software and informing about environmental issues of software usage. In order to get the implementation of the research results of the thesis going, it highlights practical implications for diverse groups of stakeholders - researchers, certifiers, public administration and professional purchasers, and environmental associations - that have been identified as being important for the practical implementation of the presented concepts and, thus, represent the target group of the doctoral thesis.
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been widely used since 1950 in various consumer products as well as in industrial applications owing to their unique properties, e.g. being hydrophobic and lipophobic at the same time. Nowadays, some of these persistent and man-made PFASs can ubiquitously be found in humans, wildlife and various environmental media. One prominent representative of concern, belonging to the subgroup of perfluorocarboxylates (PFCs) and their conjugate acids (PFCAs), is perfluorooctanoat (PFO) and its conjugate acid (PFOA). Because of its adverse effects on human health and its persistency in the environment industry has started to replace PFO(A) and related long chain chemicals (with seven and more fully fluorinated carbon atoms) with so-called short chain PFASs (less than seven fully fluorinated carbon atoms), including precursors of PFC(A)s. Also these short chain PFC(A)s are persistent and can already be found in humans, ground- and drinking water and in remote regions. However, knowledge gaps exist in understanding the partitioning and the resulting mobility of short chain PFC(A)s in the environment. This is due to the fact that partitioning data of PFC(A)s from standardised experiments can easily be biased by various artefacts, e.g. self-aggregation of the molecules. Therefore, the objectives of this thesis are (i) to quantify the partitioning of PFC(A)s into mobile environmental media, (ii) to show how results from non-standard tests can be used to assess substance properties of concern and (iii) to conclude on whether the environmental exposure to short chain PFC(A)s is of concern from a regulatory point of view. In the first part of this thesis, the environmental mobility of short chain C4-7-PFC(A)s was investigated by quantifying their partitioning under non-standardised semi-environmental conditions into mobile environmental media, focusing on water and air, and comparing it to long chain PFC(A)s. Results are: Partitioning between water and particles in the aeration tank, primary and secondary clarifier of a wastewater treatment plant (WWTP) showed no distinct differences for short chain PFC(A)s compared to their long chain homologues (Paper 1). In a water-saturated sandy sediment column short chain PFC(A)s were not retarded, whereas long chain homologues were retarded by sorption to the sediment (Paper 2). Atmospheric particle-gas partitioning showed a lower fraction sorbed to particles for short chain PFC(A)s compared to long chain ones in samples from a WWTP (Paper 3). Air-water concentration ratios based on samples from the tanks of a WWTP were found to be higher for short chain PFC(A)s compared to long chain PFC(A)s (Paper 1). Additionally, in a newly developed experimental set-up the water to air transfer was used to derive that the pKa of C4-11-PFCAs must be <1.6 instead of up to 3.8 as reported in the literature (Paper 4). Overall, in the investigated systems short chain PFC(A)s showed a higher mobility due to a more pronounced partitioning into mobile environmental media compared to long chain PFC(A)s. In the second part of the thesis it was shown how PFO(A) - owing to its persistent, bioaccumulative and toxic (PBT-)properties – was in the context of this thesis successfully assessed as a substance of very high concern according to the criteria of the European REACH Regulation (EC No 1907/2006) by using data from non-standard tests (Paper 5). In conclusion, based on the knowledge of the high environmental mobility of short chain PFC(A)s and taking into account the argumentation of the PBT-concern of PFO(A), environmental exposure to short chain PFC(A)s is of concern and existing knowledge is already sufficient to initiate measures to prevent emissions of short chain PFC(A)s and their precursors into the environment.
This paper-based dissertation deals with the concepts of economic heterogeneity and environmental uncertainty from different perspectives, and at multiple levels of abstraction. At its core sits the observation that heterogeneity and uncertainty are deeply entangled, for there would be no uncertainty without heterogeneity of options to act regarding multiple future states of the world. At the same time, heterogeneity - in the form of diversification - has been suggested as a way to reduce uncertainty in portfolio theory (Markowitz 1952). The dissertation evolves around two research foci: (1) methodological implications of heterogeneity of scientific theories in the face of empirical data (Paper 1), and (2) two different forms of uncertainty are considered, environmental risk (Paper 2) and Knightian uncertainty (Paper 3). Paper 1 develops a new framework for model selection for the special case of fitting size distribution models to empirical data. It combines Bayesian and frequentist statistical approaches with the criterion of model microfoundation, which is to select, all other things considered being equal, the model that comes with a suitable micromodel, that explains, from the perspective of the individual constituent, the genesis of the overall size distribution. The approach is subsequently illustrated with size distribution data on commercial cattle farms in Namibia. We find that the double-Pareto lognormal distribution fits the data best. Our approach might have the potential to reconcile one of the oldest debates in current economics, i.e. the one about the best model to describe and explain the distribution of economic key variables such as income, wealth and city sizes in a country. The second paper revisits the Namibian commercial cattle farm data and uses it to put some theories from the agricultural economics literature regarding farm management under environmental risk to an empirical test. We focus on the relations between inter-annual variability in rainfall (environmental risk), risk preferences, farm size and stocking rate. We demonstrate that the Pareto distribution - which separates the distribution into two parts - is a statistically plausible description of the empirical farm size distribution when ´farm size´ is operationalized by herd size, but not by rangeland area. A statistical group comparison based on the two parts of the Pareto distribution shows that large farms are on average exposed to significantly lower environmental risk. Regarding risk preferences, we do not find any significant differences in mean risk attitude between the two branches. Our analysis confirms the central role of the stocking rate as farm management parameter, and shows that environmental risk and the farmer´s gender are key variables in explaining stocking rates in our data. Paper 3 develops a non-expected-utility approach to decision making under Knightian uncertainty which circumvents some of the conceptual problems of existing approaches. We understand Knightian uncertainty as income lotteries with known payoffs but unknown probabilities in each outcome. Based on seven axioms, we show that there uniquely (up to linear-affine transformations) exists an additive and extensive function from the set of Knightian lotteries to the real numbers that represents uncertainty preferences on the subset of lotteries with fixed positive sum of payoffs over all possible states of the world. We define the concept of uncertainty aversion such that it allows for interpersonal comparison of uncertainty attitudes. Furthermore, we propose Renyi´s (1961) generalized entropy as a one-parameter preference function, where the parameter measures the degree of uncertainty aversion. We illustrate it with a simple decision problem and compare it to other decision rules under uncertainty (maximin, maximax, Laplacian expected utility, minimum regret, Hurwicz).
Against the background of recent economic attempts to explain individual economic decisions by structural and institutional factors, this thesis examined to what extent cultural norms exhibit quantitatively important explanatory power for individual economic outcomes, namely individual’s savings and working choices. While an extensive literature deals with the relation between culture and aggregate economic outcomes, those results obtained may reveal distorted cultural effects due to unobserved omitted variables at the country level. Thus, for the purpose of this thesis, four empirical studies were conducted based on individual and household level data for the USA and Germany, respectively. Due to difficulties in defining a coherent concept of culture, Chapters 2 to 4 use individual religiosity, as measured by one’s religious affiliation and religious involvement, as a proxy for culture. Using individual survey data for the USA, namely the PSID, for the years 2003 to 2009, the aim of Chapter 2 was, firstly, to analyze the extent to which religious beliefs and religious commitment are associated with distinct individual savings behavior as a basis for culture-induced heterogeneity in aggregate economic outcomes. One’s religiosity was found in the cross-sectional analysis to be a robust determinant of individual savings choices, even once I control for differences in individual characteristics. To identify the causal effect of religion on individual savings choices, secondly, the results from the multivariate analysis were verified by using the longitudinal structure of the PSID and by an instrumental variable approach, where own individual religious belief were instrumented with the share of one’s religious tradition in the region of ancestry. Neither of these approaches was able to replicate the positive relation between religious affiliation and savings behavior found in the cross-sectional analysis Although the estimates are subject to inefficiencies due to data limitations, this paper mainly sheds light on the endogeneity bias inherent in the relation between cultural factors and economic outcomes. However, taking actively part in religious activities was found to affect the amount saved positively. Thus, one may argue that religious traditions impose religious rules and establish social networks that enhance an individual’s ability and willingness to save money. As opposed to the vital religious market in the USA, Chapters 3 and 4 analyzed the relationship between individual religiosity and risk-taking preferences as well as individual financial behavior within Germany. Using German micro-data, namely the GSOEP, for the years 2003 and 2004, while controlling for the overall level of general risk assessment, evidence is provided that different religious affiliations are associated with distinct financial risk taking attitudes as well as with distinct individual propensities to trust strangers, another central determinant of a household’s financial choices. Further, the extent to which religion-induced heterogeneity in risk-taking preferences actually influences investment and trusting decisions of households in Germany was examined. As compared to the results obtained for the relation between religiosity and savings behavior in the USA, the main differences in economic attitudes and behavior in Germany occur between Christian and Non-Christian religions. However, religious networks were found in both countries to be more important for economic outcomes than religious belief. Chapter 5 purposed to replicate epidemiological studies conducted for North America (Fernández, 2007; Fernández and Fogli, 2009; Gevrek et al., 2011) in Germany using a quite smaller sample which were drawn from data provided by the GSOEP for the years 2001 to 2011. Applying probit and Tobit estimation techniques the results contradict the findings obtained by these previous contributions. While cultural norms towards labor market behavior of women, as measured by past female LFP rates in the country of own or parental origin, were found to be negatively associated with labor market outcomes for first-generation immigrant women in Germany, no statistically significant relation was revealed for the second generation. However, in accordance with the findings from Chapters 2 to 4, religiosity, and especially the Islamic belief, was showed to be negatively related to labor market outcomes of both generations.
All of the papers contained in this thesis deal with some aspect of labor market inequality. The impact of September 11th, 2001 on the employment prospects of Arabs and Muslims in the German labor market (chapter 2) examines whether the attacks on the World Trade Center and the Pentagon on September 11th, 2001 have influenced the job prospects of persons from predominantly Muslim countries in the German labor market. Using a large, representative database of the German working population, evidence from regression-adjusted difference-in-differences-estimates indicates that 9/11 did not cause a severe decline in job prospects. This result, which is in line with prior evidence from Sweden and England, is robust over a wide range of control groups. Islamistic terror and the job prospects of Arab men in Britain: Does a country's direct involvement matter? (chapter 3) examines whether the labor market prospects of Arab men in England are influenced by recent Islamistic terrorist attacks. We use data from the British Labour Force Survey from Spring 1999 to Winter 2006 and treat the terrorist attacks on the USA on September 11th, 2001, the Madrid train bombings on March 11th, 2004 and the London bombings on July 7th, 2005 as quasi-experimental events that may have changed the attitudes towards Arab or Muslim men. Using treatment group definitions based on ethnicity, country of birth and religion, evidence from difference-in-differences-estimators combined with matching indicates that the real wages, hours worked and employment probabilities of Arab men were unchanged by the attacks. This finding is in line with prior evidence from Europe. Effects of the obligation to employ severely disabled workers - findings from the introduction of the Law to Combat Unemployment among Severely Disabled People'' (chapter 4) uses new administrative data from the German Federal Employment Agency -- the Integrated Employment Biographies Sample IEBS -- to assess the impact of a mandatory employment quota for disabled workers in Germany. We use an exogenous change, introduced through the Law to Combat Unemployment among Severely Disabled People'' (Gesetz zur Bekämpfung der Arbeitslosigkeit Schwerbehinderter''), as a natural experiment and measure the change in the reemployment probability of the unemployed disabled by means of regression-adjusted difference-in-differences estimators. Our results indicate that the change in the employment quota neither enhanced nor worsened the employment prospects of the disabled. Finally, Intra-firm wage inequality and firm performance -- First evidence from German linked employer-employee-data (chapter 6) deals with the impact of wage inequality on firm performance. Economic theory suggests both positive and negative relationships between intra-firm wage inequality and productivity. This paper contributes to the growing empirical literature on this subject. We combine German employer-employee-data for the years 1995-2005 with inequality measures using the whole wage distribution of a firm and rely on panel-instrumental variable estimators to control for unobserved heterogeneity and simultaneity problems. Our results indicate a relatively small impact of wage inequality on firm performance in West Germany, while there seems to be a relationship for some inequality measures in East Germany. Further analysis shows that the relationship varies strongly with industrial relations in East Germany.
This dissertation comprises three stand-alone research papers dealing with different aspects of labor market characteristics: bonus payments and the gender pay gap; second job holding; and workers un-covered by collective bargaining. The first paper investigates whether and how non-base compensation in the form of bonus payments, overtime pay, and shift premia contributes to the gender pay gap. Unionization along with collective bargaining coverage has been on the decline on recent decades. Using German administrative data, the second paper examines which workers in firms covered by col-lective bargaining agreements still individually benefit from these union agreements, which workers are not covered anymore and what this means for their wages. The third paper studies the development and persistence of second job holding in Germany after a legislative change in the year 2003 allowed the extensive dispensation of marginal second jobs from taxes and social security contributions. Using data from the German Socio-Economic Panel, the author documents a substantial increase in second job holding in Germany since 2003 and finds in a dynamic panel model setting that there is true state dependence in second job holding.
Many dynamics are reshaping the global macroeconomics and finance. This cumulative dissertation empirically examines the impacts of two major global dynamics, the disaster risks and the China's rise, on the global economy. Chapter 1 introduces the motivation and summarizes the dissertation. Chapter 2 investigates how geopolitical risks affect financial stress in the whole financial system and its sub-sectors (banking, stock, foreign exchange, bond) of major emerging economies. Chapter 3 shows how different disaster risks (financial, geopolitical, natural-technological) can explain the returns and risk premiums of stock and housing in advanced economies between 1870 and 2015. Chapter 4 examines how the rise of China is contributing to higher economic growth in emerging economies, especially after the Global financial crisis of 2007-2008. Chapter 5 illustrates how a close trade and investment relation with China has helped African countries to reduce poverty and to improve their income distribution.
All of the papers contained in this thesis address the topic of population economics, especially in relation to labor markets. The first chapter, Introduction, gives an overview of the papers discussed in this thesis. In the second chapter, Age and Gender Differences in Job Opportunities, job opportunities for older workers are analyzed. Newly-employed women and men who are older than the age of 55 are more limited in their occupational choices than younger women and men. Different measures of segregation such as the Duncan Index and Hutchens Index show unequal distribution of jobs over age. Older women in particular face the highest segregation. Several years of the IAB Employment Sample are used in the analysis. In the third chapter, Explaining Age and Gender Differences in Employment Rates: A Labor Supply Side Perspective, the labor supply of older individuals is analyzed. The comparison of reservation wages and entry wages shows age- and gender-specific differences. Nonemployed individuals at the age of 55 and older have the highest reservation wages. Reservation wages for females are always higher than those for males. Entry wages increase with age for males, but not for females. Furthermore, the job satisfaction of women decreases with age while satisfaction with leisure tends to increase. This may explain why employment rates for females are lower than for males. The German Socio-Economic Panel (GSOEP) data is used in the paper. In the forth chapter, Somewhere over the Rainbow: Sexual Orientation Discrimination in Germany, sexual orientation-based differences in income are analyzed. Although Germany has an anti-discrimination law that has explicitly prohibited discrimination on the basis of sexual orientation since 2006, there are significant income differences for gay men and lesbian women. While gay men have an income discount of 5 to 6 percent relative to married heterosexual men, lesbian women have an income premium of 9 to 10 percent relative to heterosexual married women. These differences within the gender types can be explained partially by selection into specific occupations and sectors. One wave of the German Mikrozensus data is used in the analysis. The fifth chapter, A Note on Happiness in Eastern Europe, is no more related to Germany, but takes an international position. Estimations on life satisfaction show typical results, such as a u-shaped effect in relation to age. Marriage and a good state of health have positive effects on life satisfaction or utility, while individual unemployment has a negative effect. Several years of the European Values Study (EVS) and the World Value Survey (WSV) are used in the paper. The thesis is finished by a final chapter, Conclusion
This cumulative dissertation embraces four empirical papers addressing socio-economic issues relevant to policy-makers and society as a whole. These papers cover important aspects of human life including health at birth, life satisfaction, unemployment periods and retirement decisions. The analyses are carried out applying advanced econometric methods and are based on data sets consisting of survey data as well as administrative records. The first joint paper investigates the causal impact of prenatal exposure to air pollution on neonatal health in Italy in the 2000s combining detailed information on mother's residential location from birth certificates with PM10 concentrations from air pollution monitors. Variation in local weekly rainfall is exploited as an instrumental variable for non-random air pollution exposure. Using quasi-experimental variation in rainfall shocks allows to identify the effect of PM10, ruling out potential bias due to confounder pollutants. The paper estimates the effect of exposure for both the entire pregnancy period and separately for each trimester to test whether the neonatal health effects are driven by pollution exposure during a particular gestation period. This information enhances our understanding of the mechanisms at work and help prevent pregnant mothers from most dangerous exposure periods. Additionally, the effects of prenatal exposure to PM10 are estimated by maternal labor market status and maternal education level to understand how the pollution burden is shared across different population groups. This decomposition allows to identify possible mechanisms through which environmental inequality reinforces the negative impact of early-life exposure to air pollution. This study finds that average PM10 and days with PM10 level above the hazard limit reduce birth weight, gestational age, and measures of overall newborn health. Effects are largest for third trimester exposure and for low-income and less educated mothers. The second joint paper updates previous findings on the total East-West gap in overall life satisfaction and its trend by using data from the German Socio-Economic Panel for the years 1992 to 2013. Additionally, the effects are separately analyzed for men and women as well as for four birth cohorts. The results indicate that reported life satisfaction is, on average, significantly lower in East than in West German federal states and that part of the raw East-West gap is due to differences in household income and unemployment status. The conditional East-West gap decreased in the first years after the German reunification and remained quite stable and sizable since the mid-nineties. The results further indicate that gender differences are small. Finally, the East-West gap is significantly smaller and shows a trend towards convergence for younger birth cohorts. The third joint paper explores the effects of a major reform of unemployment benefits in Germany on the labor market outcomes of individuals with some health impairment. The reform induced a substantial reduction in the potential duration of regular unemployment benefits for older workers. This work analyzes the reform in a wider framework of institutional interactions, which allows to distinguish between its intended and unintended effects. The results based on routine data collected by the German Statutory Pension Insurance and a Difference-in-Differences design provide causal evidence for a significant decrease in the number of days in unemployment benefits and increase in the number of days in employment. However, they also suggest a significant increase in the number of days in unemployment assistance, granted upon exhaustion of unemployment benefits. Transitions to unemployment assistance represent an unintended effect, limiting the success of a policy change that aims to increase labor supply via reductions in the generosity of the unemployment insurance system. The fourth, single-authored paper explores how an increase in the early retirement age affects labor force participation of older workers. The analysis is based on a social security reform in Germany, which raised the early retirement age over several birth cohorts to boost employment of older people and ultimately alleviate the burden on the public pension system. Detailed administrative data from the Federal Employment Agency allow to distinguish between employment and unemployment as well as disability pensions and retirement benefits claims. Using a Regression Kink design in a quasi-experimental framework, the author shows that the raised early retirement age had positive employment effects and negative effects on retirement benefits claims. The results also show that some population groups are more sensitive to a reduction in retirement options and more likely to seek benefits from other government programs. In this respect, the author finds that workers in manufacturing sector respond to the raised early retirement age by claiming benefits from the disability insurance program designed to compensate for reduced earnings capacity due to severe health problems. The treatment heterogeneity analysis further suggests that high-wage workers are more likely to delay exits from employment, which is in line with incentives but might also indicate an increased inequality within the affected birth cohorts induced by the reform. Finally, women seem to rely on alternative sources of income such as retirement benefits for women, or spouse's or partner's income not observed in the data. All things considered, workers did not adjust to the increased early retirement age by substituting early retirement with other government programs but rather responded to the reform in line with the policy intent. At the same time, the findings point to heterogeneous behavioral responses across different population groups. This implies that raising the early retirement age is an effective policy tool to increase employment only among older people who have the real choice to delay employment exits. Therefore, reforms that raise statutory ages should ensure social support for workers only marginally attached to the labor market or not able to work longer due to potential health problems or other circumstances.
This dissertation is based on three empirical studies on the thematic complex of the comparative advantages of self-employment and business start-ups out of unemployment. The first study examines the characteristics of persons who present a broad range of experience in terms of professional competencies. The extent to which self-reported entrepreneurial competence and the assessment of professionally self-employed activities correlate with the number of professional competencies acquired is examined in particular. It emerged from previous studies that the tendency to establish new businesses increases with the variety of experience. More recent studies show, however, that different causes may lie behind this correlation. The results of this study show that both entrepreneurial competence and the estimation of self-employment increase with the number of professional competencies. However, the analyses would indicate that entrepreneurial competence (self-assessment) is more strongly correlated and that an actual increase in qualifications lies behind the self-assessed entrepreneurial competence. Moreover, it emerges that self-assessed entrepreneurial competence increases at decreasing marginal rates with the number of professional competencies. The second study examines the extent to which professional background and, in particular, the professional and employment experience of an individual influence the duration he or she remains in self-employment. This is studied on the basis of data from a survey of founders who become self-employed out of unemployment. The study is based on the idea that individual characteristics can be used productively in different forms of employment and that specific competence and comparative characteristics affect the time-dependent exit from self-employment. The results initially confirm previous findings, in particular that firm characteristics do not play a very significant role in the decision to start up a business from a position of unemployment. Broad-based qualifications plus business skills, a high level of intrinsic motivation for self-employment and exploitable professional experience display a strong positive correlation with the duration in self-employment; this would suggest corresponding comparative advantages for self-employment. However, business skills alone reduce the time-dependent probability of survival in self-employment and accelerate exits into employment. The third study analyzes features of local labor markets in terms of their influence on the duration of self-employment. The basis of the study is provided by process-produced data generated by the German Federal Employment Agency on the employment biographies of individuals who received support in establishing businesses with a view to exiting unemployment. Individual characteristics were examined in addition to regional determinants. The idea behind the study is that local labor market conditions can have different comparative effects on income possibilities in both positions of employment and self-employment. The exit from self-employment is described as a change in work activity which arises following the evaluation of different income options. The results show that local labor market conditions have a considerable influence on the duration of self-employment and that the effect of local labor market conditions is very complex. The results would prompt the expectation that a one-dimensional perspective based on the local unemployment rate does not provide an adequate measure of general economic conditions. Increasing regional unemployment reduces the duration of self-employment while increasing uncertainty on the local labor market results in its extension. Moreover, all local characteristics display reducing to reversing marginal effects. Tests of individual characteristics show that persons from small businesses, master craftsmen and foremen, and persons with high income premiums remain longer in their last employment situation than the controls. These characteristics are clearly associated with comparative advantages for self-employment. The study also corroborates the impression that people with business backgrounds quickly leave self-employment for employed positions.
In this dissertation, the author focuses on the link between (internal) corporate governance structures and processes and firms financial reporting quality. Specifically, the dissertation aims to provide insights into the following general research question: What is the effect of different corporate governance stakeholders on the financial reporting quality of a firm? The author provides insights into this question through three different articles. Paper #1 explores the relationship between family firm status and earnings management and synthesizes and explains previous research findings with the help of meta-analytic methods that are still uncommon in financial accounting research. The authors find a negative relationship between family firms and earnings management on average across 37 primary studies (and 305 effect sizes in total). Furthermore, they show that the considerable variation in size and direction of primary effect sizes can be explained by researchers choice of study design, earnings management proxy and different institutional settings. The second paper explores institutional owners as a different set of shareholders and their impact on financial reporting quality. The study enables the authors to compare the results against the backdrop of the previous chapter and to see different rationales that managers in institutionally-owned companies might have to engage in earnings management. Here, the authors study 511 effect sizes from a total of 87 primary studies and find that the average effect is slightly negative, meaning institutional owners on average can get more transparent earnings figures from the companies they invest in. Similar to the work they did on family firms, they find considerable heterogeneity between results from primary studies. Specifically, their multivariate meta-regression models can explain 26% of the variability in effect sizes, mainly attributable to study design choices. The third paper is concerned with managers and how managerial personality drives the propensity to engage in fraudulent accounting activities. The author uses a primary sample of 956 professionals, who work in accounting and finance departments, and ask them to rate their immediate superior on dark triad personality traits, as well as common actions taken by management to obscure and manipulate earnings figures. He finds that managers with high ratings for dark triad personality traits engage to a greater extent in fraudulent accounting practices, than managers scoring low on the dark triad scale. Moreover, the author can show that traditional risk management mechanisms, like internal audit departments, are only partially effective. Specifically, he finds that only internal audit departments that are fully staffed by external personnel can curb the adverse effect of dark triad managers on financial reporting quality. This suggests that managers with dark personalities can take advantage of mixed or entirely in-house internal audit departments. Overall, this dissertation contributes significantly to both literature streams of corporate governance and financial reporting quality. This work can explain a significant degree of heterogeneity in previous findings on the link between different kinds of ownership and earnings management. Further, it stresses that the considerable variation in current findings is not mainly attributable to cross-country differences, as previously suggested, but in no small part attributable to study design features. Finally, the author can provide additional evidence on current research linking executive personality traits and financial reporting practices.
Essays on Say-on-Pay: theoretical analysis, literature review and empirical evidence from Germany
(2019)
The dissertation contains four journal articles together with a framework manuscript. The overall subject is the so-called Say-on-Pay (SOP) vote. SOP is a law that enables shareholders to vote on the appropriateness of executive compensation during the firms’ annual general meeting. The dissertation investigates SOP votes from different angles. While the framework provides a background for the relevance of the work, outlines existing research gaps, covers an in-depth discussion and concludes relevant research questions, the four articles present the essence of the dissertation. The first article is a theoretical paper on the recent advances of behavioural agency theory. It serves as a theoretical foundation for the empirical work of the dissertation. Although principal-agent theory has gained a prominent place in research, its negative image of self-serving managers is frequently criticized. Consequently, scholars advocate the utilization of positive management theories, such as stewardship theory. This paper reviews the literature of both theoretical concepts and describes how behavioural characteristics allow for a mutually beneficial symbiosis of the two theories. The second article establishes the foundation of the scholarly knowledge in the field by systematically reviewing the empirical literature. The review covers 71 empirical articles published between January 1995 and September 2017. The studies are reviewed within an empirical research framework that separates the reasons for shareholder activism and SOP voting dissent as input factor on the one hand and the consequences of shareholder pressure as output factor on the other. The implications are analysed, and new directions for further research are discussed by proposing 19 different research questions. Building on the research gaps defined in the literature review, the third article is an empirical manuscript. In this paper, a hand-selected sample of 1,676 annual general meetings with 268 management-sponsored SOP votes in 164 different companies between 2010 and 2015 in Germany is analysed. The analysis focused on the structure, rather than the level, of executive compensation by applying a sample-selection model and panel data regression. Finally, the fourth paper investigates the rare setting of voluntary SOP votes. Using 1,841 annual general meetings of listed firms in Germany between 2010 and 2016, the effects of financial and non-financial (sustainable) performance on SOP voting likelihood and voting results are tested.
In 2013, the European Commission adopted the so called "Entrepreneurship 2020 Action Plan" to ease the creation of new ventures and to support the takeover of existing firms. The goal is to create a supportive environment for entrepreneurs to thrive and grow (European Commission 2013). This shows that the European Union puts its efforts to support small firms as they are seen as means for Europe's sustainable economic growth. However, the successful processes of growth and investment are complex and depend on different determinants. The present thesis focuses on the firm level and analyzes in three independent articles: how small firms invest over time, how new ventures grow and which variables influence growth, how small firms grow after business takeover and which variables influence growth. The framework that connects these articles forms the content-related focus on the early stage of development of small firms and the methodological and analytical approaches that comply with up-to-date and adequate statistical analysis techniques. Supported by an extensive dataset, which is the foundation of all three articles, it is possible to investigate empirically different open research questions using bivariate and multivariate analysis techniques. Thus, this thesis also serves the research needs for more multivariate analyses for small firms, for which so far mainly cross-sectional studies have been conducted.
This research work aims to create a theoretical base for new urban planning guidelines involving a comprehensive study of housing in Damascus with emphasis on social and cultural factors. The research starts with a historical review of the Muslim City in general and distinguishes between cities that existed before Islam and then were conquered and modified by Muslims and cities established by Muslim Authority. The focus is only on the residential quarters in the city and the local market, mosque and etc (outside the old walled city of Damascus). Other Muslim city urban elements such as Grand mosque, caliph's residency, Citadel and etc. are not in the scope of this study. A brief historical review of Damascus before and during Islam and the development of residential quarters are illustrated. Later, the study analyzes the traditional residential quarter and explores the building guidelines that governed the evolution of the built form of the quarter. Then, the study explores the multi-faceted changes (economic, social and political) that the Middle Eastern region went through, in the last century, in general and the effect of those changes on the city form, case of Damascus. The effect will be traced through examining the decrees that the Authority issued in order to govern land reform and manage public and private domains. Then, the study looks at the ramifications of those decrees on the urban form of Damascus. It also investigates the decrees that were the guide for new planning and organizing developments. The study will inspect the end products of the planning and organizing process by studying several cases of building permits. Then, provides morphology of the new residential sub-quarter and its urban form. Based on lessons learned from the previous decades of housing policy, the study will recommend foundation for governmental norms to produce responsive physical and social urban forms.
On 25 October 2016, the European Commission presented a proposal for a directive on a Common Corporate Tax Base (CCTB Proposal), which contains a comprehensive concept for the harmonisation of profit calculation regulations within the EU. Against this current background, the objective of the present work is to contribute to the implementation of the CCTB by identifying ambiguities and conceptual weaknesses in the design of the profit determination system of the CCTB Proposal and developing concrete recommendations for action for adjustments in the course of the further legislative procedure. In the first article, selected profit calculation rules of the CCTB Proposal will be analysed in detail and compared with the provisions on profit calculation under German commercial and tax law and the International Financial Reporting Standards (IFRS) recognised across member states. Based on the legal comparison, questions of interpretation and inadequacies of the profit calculation system will be considered and proposals for adjustments to various regulatory areas will be submitted. Furthermore, in the second article, within the framework of a holistic study, expert interviews will be used as an empirical-qualitative research design to generate reliable assessments on the part of the various stakeholder groups affected by the implementation of the future directive or involved in its elaboration. The results show the extent to which the profit determination rules of the CCTB Proposal in their current form are suitable for national and EU-wide implementation and in which areas the various expert groups still see concrete need for adaptation. Based on these expert assessments, the third article finally develops a proposal to reduce the threat of legal uncertainty in interpretation issues criticised by the experts. Based on economic maxims developed by the European Commission and existing accounting principles of the current CCTB Proposal, the EU Accounting Directive and IFRS, a system of specific European tax principles will be developed which could be implemented within the framework of the CCTB Proposal.
In the early 1990s the European Commission and the national governments of the EU member states initiated an extensive deregulation and liberalization process in the European railway industry. Prior to this process, the European railway industry was characterized by loosely connected national monopoly railway companies which faced severe losses of transportation market share and required increasing subsidies. Overall, this system was not what a single European market needed: an integrated transport system that provides reliable and fast cross-border transportation of goods, services, and people. The main elements of the reforms have been the separation of infrastructure management from transport operations, the implementation of interoperability among the national railway systems, the assurance of third-party access to the infrastructure, and the introduction of independent railway regulatory systems. In general, the intention of the reforms has been to enhance competition by opening the market and to improve the economic performance of the European railway industry. The objective of this thesis is to analyze the effectiveness of the European railway deregulation process in enhancing efficiency and productivity in the European railway industry. For that purpose three empirical papers are introduced that use non-parametric and parametric benchmarking methods to evaluate the impact of different production technologies and country- and firm-specific environmental and regulatory conditions on efficiency and productivity. The first paper, ‘Testing for Economies of Scope in European Railways: An Efficiency Analysis’, conducts a pan-European efficiency analysis to investigate the performance of European railways with a particular focus on economies of vertical integration. We test the hypothesis that integrated railways realize economies of scope and, thus, produce railway services with a higher level of efficiency. To determine whether joint or separate production is more efficient, we apply an innovative two-stage data envelopment analysis super-efficiency model which relates the efficiency for integrated production to a reference set consisting of separated firms which use a different production technology. We find that for a majority of European railways economies of scope exist. The second paper, ‘Productivity Growth in European Railways: Technological Progress, Efficiency Change and Scale Effects’, analyzes the efficiency and productivity of the European railway sector in the period of deregulation (1990-2005). Using a stochastic frontier panel data model that controls for unobserved heterogeneity a distance function model is estimated in order to evaluate the sources of productivity growth: technological progress, technical efficiency change and scale effects. The results indicate that technology improvements were by far the most important driver of productivity growth, followed by gains in technical efficiency, and to a lesser extent by exploitation of scale economies. Overall, we find an average productivity growth of 39 percent within the sample period. The third paper, ‘European Railway Deregulation: The Influence of Regulatory and Environmental Conditions on Efficiency’, investigates the impact of regulatory and environmental conditions on technical efficiency of European railways. Using a panel data set of 31 railway firms from 22 European countries from 1994 to 2005, a distance function model, including regulatory and environmental factors, is estimated using stochastic frontier analysis. The results obtained indicate positive and negative efficiency effects of different regulatory reforms. Furthermore, estimating models with and without regulatory and environmental factors indicates that the omission of environmental factors, such as network density, substantially changes parameter estimates and, hence, leads to biased estimation results. The last chapter of the thesis summarizes the results of the three empirical analyses. It contains overall conclusions, highlights implications for economic policy, and provides directions for further research.
The doctoral dissertation deals with the problems of the diagnosis of rolling bearings using recurrence analysis. The main topic is the influence of radial internal clearance on the change of dynamics in a self-aligning double-row ball bearing with a tapered bore, in which the axial preload can control this parameter in a wide range. The dissertation began with an analysis of the state of knowledge. In the next part of the dissertation, the thesis was formulated and activities related to its proving were defined. The theoretical part was supplemented with the basics related to vibroacoustic diagnostics of rolling bearings and presented methods that can be used for their diagnostics. The research on proving the thesis was started with the preparation of a mathematical model in which a change in the damping coefficient in the field of radial clearance was adopted, a difference in the clearance value for a given row of balls was proposed, and the influence of shape errors and radial shaft endplay on the dynamics of the tested bearing was taken into account. During the dynamics tests, the radial clearance was adopted as a bifurcation parameter, and on the basis of the bifurcation diagram, it was possible to indicate the characteristic areas of bearing operation due to the radial internal clearance. In order to verify the model, experimental tests were carried out with a series of bearings in which the radial clearance was changed in a wide range possible to be physically realized. Recurrence analysis was used for both the dynamic response obtained from model and experimental studies. Owing to the comparative analysis of the dynamic response, recurrence quantificators were selected that are most susceptible to changes in radial clearance to bearing dynamics. Moreover, as a result of the research, it was possible to select a narrow range of radial clearance, ensuring the smoothest operation of the tested bearing.
Since its establishment, the African Union (AU) has assumed an important role in matters of peace and security on the continent. This doctoral dissertation is dedicated to its conflict and crisis interventions and seeks to identify as well as subsequently explain the broader patterns that have emerged. The dissertation posits that neither the AU's regime-serving roots, which emphasize the primacy of incumbents' parochial interests, nor the AU's problem-solving commitment, which emphasizes the pursuit of its declared organizational mission, can convincingly explain these patterns on their own. Instead, we should understand the AU as being driven by two different logics of cooperation at the same time: a problem-solving and a regime-serving logic. Across its three constitutive articles, the dissertation makes empirical as well as theoretical contributions to the existing literature. Empirically, it offers a broad and systematic analysis of AU interventions over time, across different intervention types, and without bias towards high-profile cases. The novel dataset, on which the dissertation builds, constitutes the hitherto most comprehensive effort to capture the AU's responses to crises and conflicts. Theoretically, the dissertation develops a set of testable theory-driven expectations based on the notion of two different logics of cooperation. While identifiable in the literature on the AU and linking to broader existing debates on international cooperation, the dissertation breaks ground by clearly outlining the implications of each logic and bringing them together under a single theoretical framework. Jointly, the articles provided strong evidence that the AU is indeed driven by both a problem-solving and a regime-serving logic of cooperation, and that this serves as the foundation for explaining the AU's broader intervention patterns. This contributes not only to a better understanding of AU interventions but also has a chance to enrich other important debates, including the debates on African regionalism, comparative regionalism, and multilateral interventions.
Destination websites, which are maintained by destination marketing/management organisations (DMOs), are a key source of information for tourists in the pre-trip phase. DMOs are increasingly applying experiential marketing on their websites to support positive pre-travel online destination experiences (ODEs) and make the vision of the holiday as vivid as possible. However, research into technology-driven travel experiences is still in its infancy. In particular, a theoretical understanding of the nature of ODEs arising from destination websites is still lacking. Therefore, this dissertation is dedicated to an extensive investigation of ODEs on destination websites in the pre-travel phase. The aims were to analyse the influences of experiential design on ODEs, explore the ODE dimensions, and develop and validate a measurement tool for assessing the ODE values of destination websites. In the first qualitative multi-method study (eye-tracking, retrospective think-aloud protocols, semi-structured interviews, and video observations), the objective was to gain an in-depth understanding of the ODE facets in the travel inspiration phase. It was found that the experience dimensions adopted in previous research regarding the product-brand context (sensory, affective, intellectual, social, and behavioural dimensions) also occurred in the ODE context but exhibited some particularities, such as a future-oriented affective component (affective forecasting). Moreover, a supplementary spatio-temporal experience dimension was identified. An online field experiment was subsequently conducted and aimed at assessing the effects of applying experiential marketing on destination websites on ODEs in the travel inspiration phase. Based on the findings of Study 1, an initial attempt at developing an ODE measurement instrument was made and the ODE dimensionality tested. The results showed the theoretically relevant experience dimensions to be less differentiated compared to the product-brand context; instead, they merged into a holistic ODE encompassing several experience facets. Furthermore, it was shown that the application of experiential design enhanced ODEs; however, considering the subjectivity of experiences, the effect was rather small. Accordingly, complex multi-media elements do not automatically increase the experiential effect. In the third study, a quasi-online field experiment was conducted, simulating the travel information phase (higher involvement than Study 2) to re-assess the ODE dimensions and develop and validate a measurement instrument. The results showed the overall ODE to be reflected by two interrelated dimensions that aligned with the dual process theory: hedonic and utilitarian experiences. The facets identified in the first study were largely reflected in these two overarching components. Moreover, a reliable, valid, and parsimonious second-order measure for assessing ODEs was proposed. Overall, the results yielded by this dissertation enhance the scientific understanding of the technology-empowered tourist experience in the currently under-researched pre-travel experience phase. In addition, by proposing a new scale for the measurement of ODEs, this dissertation provides useful methodological advancements that can pave the way for further research in this field.
The majority of empirical studies that centre on exporter performance and the determinants of export performance have focused mainly on the manufacturing sector, largely because there are very few datasets that facilitate a detailed investigation into the service sector. In 2008, however, the German Federal Statistical Office and the statistical offices of the Federal States released the German business services statistics panel (this dataset is described in more details in Chapter 2). Thus, for the first time, appropriate panel analyses of the export behaviour of German business services firms became possible. This thesis uses this panel dataset and contributes to the literature on the microeconometrics of international trade by providing evidence concerning the German business services sector. Overall, the results noted for exporter performance in the German business services sector correspond with those from the manufacturing sector. Chapter 3 shows that, similar to the manufacturing sector, exporting German business services firms are more productive and clearly larger (in terms of turnover and number of employed persons) than non-exporters, even when it is controlled for size and industry. Further, business services enterprises that export pay higher average wages (even when controlling for size and industry). When controlling for unobserved, time-invariant characteristics, the significant differences between exporters and non-exporters relative to productivity or average wages disappear, while significant export premia associated with the size variables continue to exist, but on a much smaller scale. Concerning the hypothesis that better performing enterprises self-select into export markets, the results indicate that in the business services sector as in the manufacturing sector, enterprises that begin to export are larger than non-exporters, even two years before they commence exporting operations. Regarding productivity (in terms of turnover per employed person) and average wages, the results were statistically significant only for business services enterprises in Germany’s western region. Aside from these similarities with the manufacturing sector, Chapter 4 presents evidence which suggests that, contrary to firms in the manufacturing industries, German business services firms do not benefit from exporting in terms of higher rates of profit. Chapter 4 documents a negative profitability differential of services exporters compared to non-exporters, and finds that export-starters in the business services sector are less profitable than non-exporters, even two years before they begin to export. Further, the estimated dose-response function, which is used to investigate the causal impact of exports on profits, shows an s-shaped relationship between profitability and firms’ export-sales ratio. Enterprises with a very small share of exports in total sales have a lower rate of profit than non-exporting firms. Then, with an increase in export intensity, the rate of profit increases as well. However, even at the maximum, the average profitability of the exporters is not, or is only slightly, higher than the average rate of profit of the non-exporting firms. Chapter 5 investigates the question which factors determine the export performance of German business services firms by estimating a model of the firms’ export intensity decision. Overall, the results support most of the explanations of export behaviour found in the literature for both service firms and manufacturing firms, such as the positive effects of size, human capital, and productivity. Yet when controlling for unobserved heterogeneity, the picture changes; notably, in the model with fixed effects, the significance of productivity and human capital disappears. This indicates that these variables are not positively related to the export performance per se, but are related instead to unobserved time-constant characteristics. Size still has a significant positive effect on exporting when controlling for unobserved effects. Finally, Chapter 6 considers the impact of the 2004 EU enlargement on service enterprises close to Germany’s eastern border by using regression-adjusted difference-in-differences estimators. The results suggest a small negative impact associated with the EU enlargement on export intensity and the turnover of large enterprises with an annual turnover of €250,000 or more, and no effect on the share of exporters and the turnover profitability of these enterprises. For small enterprises close to Germany’s eastern border, an increase in turnover and a decrease in profitability relative to other small enterprises are noted.
This dissertation analyses external appointees and successions on boards and consists of three papers which are all empirical in nature. It provides insights into the present literature from a meta-perspective, enlarges the understanding of external successions to German executive bank boards and extends the rare number of studies on the internal supervisory bodies of bank institutions. The first paper highlights the existing literature: conducting a literature search process, the paper aggregates 102 empirical results from 28 journal articles and working papers published between 1990 and 2017. The meta-analysis focuses on how researchers address the build-in issue that outsiders are not randomly assigned to firms. The results reveal that the relationship of outside successions and performance varies significantly with the methodological characteristics of the original studies. The following two papers concentrate on successions in banking institutions. More specifically, the second study examines the appointments of executive directors external to the bank and the consequences of that appointment on bank performance. The study addresses in particular alternative explanations, i.e. outside selection and/or joint endogeneity, while examining external executive appointments and their consequences on bank performance. The second empirical paper lend significant support to the view that some outsiders are better predisposed to helping the bank turn around poor performance and that the selected proxies of managerial ability, which are based on the historical return on assets and risk-return efficiency measured at outsiders' former banks, are able to identify such good outsiders. Finally, the third paper considers the link between the executive and the supervisory board. The study points to the conclusion that newly appointed executives to the supervisory board differ from their non-appointed counterparts with a particular set of experiences. The study provides evidence for the view that the pre-appointment financial situation, measured by several proxies of bank risk and performance, has significant influence on the decision to appoint such an experienced member to the supervisory board. This dissertation is framed by an introduction and concluding chapter where the author reflects on the research questions of her empirical studies, summarizes the results and identifies some possibilities for future research.
To be prepared for one´s own career is a major task during career development. However, existing research has primarily focused on adolescence in the transition from school to work while research on career preparation among university students, that are challenged by successfully transiting from university to work, are lacking so far. Thus, this cumulative dissertation studies career preparation in terms of career decidedness, planning, confidence, and career engagement using large samples of German university students and alumni as well as a variety of quantitative methods like latent state-trait analysis, cross-lagged analysis, and mediation analysis with multiple mediators. In the first paper, the stable component of career indecision is investigated with longitudinal data stemming from two samples with different time lags (Sample 1: N = 363, 7 weeks; Sample 2: N = 591, 6 months). Furthermore, the combined and unique effects of career indecisiveness and generalized indecisiveness on life satisfaction are examined using a sample consisting of 469 university students. Results indicate that career indecision is determined by a stable component (i.e., trait career indecisiveness) that is associated with lower core self-evaluations, lower occupational self-efficacy, and higher perception of career barriers. Additionally, results indicate that the stable career indecision component explains 5% of the variance in student life satisfaction beyond self-evaluated generalized indecisiveness. The second paper deals with the relationships of vocational interest characteristics - interest congruence, interest differentiation, and general interest level (elevation) - with several indicators of career preparedness (i.e., career planning, occupational self-efficacy beliefs, career decidedness, and career engagement) among a sample of 239 university students. Controlling for sociodemographic variables, multiple regression analyses revealed that differentiation is positively associated with career decidedness and career engagement and elevation is positively related to occupational self-efficacy beliefs and career engagement. The third paper investigates how protean career orientation (PCO) is related to vocational identity clarity and occupational self-efficacy. Study 1 reports a 1-year, three-wave cross-lagged study among 563 university students and established that PCO preceded changes in identity and self-efficacy - but not the other way around. Based on a 6-month longitudinal study of 202 employees, Study 2 shows that identity clarity and self-efficacy mediated the effects of PCO on career satisfaction and proactive career behaviors. PCO only possessed incremental predictive validity regarding proactive career behaviors. However, specific direct or mediated effects of PCO on job satisfaction could not be confirmed. The fourth paper explores the relationships between narcissism and two indicators of career success (i.e., salary and career satisfaction) among a group of young professionals (N = 314). A model proposing that the effect of narcissism on career success is mediated by increased occupational self-efficacy beliefs and career engagement was assessed. While correlations between narcissism and the two indicators of career success were minimal, the results show a significant indirect effect on salary via occupational self-efficacy and indirect effects on career satisfaction via self-efficacy and career engagement. Overall, the different studies corroborate the crucial role of career preparation for a successful start into working life. In sum, this dissertation contributes to literature on vocational psychology by providing novel insights in terms of facilitators and outcomes of career preparation among university students and graduates. Theoretical and practical implications are discussed, and promising directions for future research are identified.
The global coffee market is connected to many sustainability issues like the persisting poverty of coffee farmers, and degrading ecosystems. Many interventions, from state-led regulation to industry-led certification processes, exist, that try to change global value chains to shift societies back on more sustainable trajectories. To this date, it is still under debate if these interventions are an effective means to change global value chains. With climate change and persisting issues of social justice as strong accelerators, calls are increasingly made for a radical transformation of global production and consumption patterns. Many frameworks try to inform research and real-world policies for a transformation of global value chains. In this dissertation, the author uses the framework of the practical, political and personal sphere proposed by O'Brien and Sygna (2013) highlighting that the interactions between these three spheres bare the greatest potential for a transformation towards sustainability. However, in this dissertation, the author argues that it is exactly at the nexus between the three spheres of transformation where barriers towards a fundamental shift of systems occur. He, therefore, uses three perspectives to bring empirical nuance to the problems that arise on the interplay between the different spheres of transformation. (1) The scientific perspective: using a systematic review of alternative trade arrangements; (2) the producer perspective: facilitating a participatory network analysis of social-ecological challenges of Ugandan coffee farmers and their adaptive management practices; (3) the consumer perspective: through the use of a German consumer survey and a structural equation model to investigate into the Knowledge-Doing-Gap end-consumers are facing. Through the results from the scientific perspective, the author is able to show that most of the research is investigating the certified market and that the effectiveness of labels rarely exceeding the practical sphere. His empirical research on the producer perspective highlights that Ugandan coffee farmers facilitate a variety of on-farm crop management (practical sphere) but their support structures rarely exceed informal exchange with neighboring communities (political sphere). Exchange with governmental actors and global traders is happening but has been assessed as not sufficient to cope with the social-ecological challenges the producers are facing. Through the results of the consumer perspective, the author is able to highlight that even though end-consumers have pro-sustainable attitudes (personal sphere) they are facing situational constraints (political sphere) that create a gap between their attitudes and the respective behavior. Using these empirical insights about drivers and barriers for a transformation he proposes that frameworks, aiming to inform research and policies, need to include two aspects: (1) the notion of a forced transformation; and (2) the translational capacity of the frameworks to create meaningful interdisciplinary discourses in different contexts. The author, therefore, propose two approaches:(1) a fourth sphere, called the "planetary force" to include the notion of a forced transformation that is already happening in different contexts, highlighted by the producer perspective in this dissertation; and (2) the consequent use of methods that create interdisciplinary exchange and rigorous testing.
Uranine (sodium fluorescein, UR) has been routinely used in hydrological research to monitor surface and subsurface water flow, transport and mixing processes since the end of nineteenth century. Based on such obtained data, further conclusions can be drawn on the spread and behavior of pollutants (partly on models). Use of UR for qualitative (visual) studies of underground contamination is common, however data available on its environmental behavior (e.g., conversion, degradation or formation and fate of the transformation products, TPs) are incomplete or not readily comparable. UR observations of biodegradation are still speculative. S-metolachlor (SM) is a popular worldwide chloroacetamide herbicide, which highly correspond to the global pesticide use. It is offered on the French market as an effective multicrop herbicide against annual grasses and certain broadleaf weeds under the trade name Mercantor Gold (MG). Photodegradation contributes to the fate of SM in the aquatic environment. TPs were already found in surface and groundwater. However, further fate and assessment of the TPs was not done. Moreover, adjuvants in MG´s formula can affect the solubility, biodegradation, photolysis and sorption properties of the active compound SM. TPs can have different properties (e.g. more mobile, toxic or present at higher concentrations) that enable them to reach the environmental compartments not affected by the parent compound (PC) itself. To assess the ecological impact of pesticides, tracers, and their respective TPs on water organisms, their behavior can be investigated in laboratory screening biodegradation tests. Yet, incomplete data was available on SM, MG and UR transformation or their photo- TPs´ fate in surface and water-sediment systems. The combination of photolysis with aerobic biodegradation in order to identify persistent photo-TPs could provide new insight into the environmental behavior of the selected compounds. Therefore, principle of this thesis was to 1) identify the impact of MG´s adjuvants on the biodegradation, photolysis (Xe lamp) and sorption compared to the SM alone, 2) examine the photolysis and biodegradability of UR 3) monitor the primary elimination (photolysis) of the PCs by HPLC (-UV, -FLD) and measure the degree of mineralization by means of nonpurgeable organic carbon (NPOC) 4) elucidate the photo-TPs of SM, MG and UR by using LCMS/ MS 5) analyze biodegradability of the photo-TPs in order to determine their fate and persistence in aquatic environment 6) conduct in silico toxicity predictions (pesticides) in human (carcinogenicity, genotoxicity and mutagenicity) and eco-toxicity (microtoxicity, bioconcentration factor and toxicity in rainbow trouts). SM, MG and UR were found not readily biodegradable in Closed Bottle test (CBT), Manometric Respiratory test (MRT) and in water-sediment test (WST). Chemical analysis of photolysis samples showed higher elimination of SM in MG compared to SM alone whereas UR displayed high primary elimination rate in general. The overall low degree of mineralization indicated that abundant photo-TPs were formed. Furthermore, the photo-TPs were found not biodegradable in performed biodegradation tests. Only small degradation rates for UR could be observed in the CBT and WST. Additionally, in the MRT and WST new bio-TPs were generated from the photo-TPs of SM and SM in MG. Obtained results suggest that the MG formulation did not significantly affect the biodegradation, however it influenced the diffusion of the active substance (SM) to sediment and potentially affected the photolysis efficiency, which might result in faster formation of photo-TPs in the environment. In silico predictions showed that for many endpoints, biotransformation might lead to an increased toxicity in humans and to water organisms compared with the parent compound SM. No indications were found for UR toxicity. Still, target-oriented investigations on long term impacts of photo-TPs from UR are warranted. The present work demonstrates that a combination of laboratory tests, analytical analysis and in silico tools result in valuable information regarding environmental fate of the TPs from selected compounds. Furthermore, it was shown that photo-TPs formed in the aquatic environment should be taken into account not only the parent compound and its decay.
The principle of this thesis was to study the environmental fate of three highly used psychotropic drugs and this achieved through: 1) examining the biodegradability of TMI, DMI and CPTX, 2) studying the behaviour of TMP, DMI and CPTX in photodegradation tests using Xe and UV lamps with studying the effect of different environmental conditions on their UV-photodegradation behaviour, 3) monitoring the primary elimination of TMP, DMI and CPTX during photodegradation and biodegradation tests using HPLC, and measuring their degree of mineralization by means of dissolved organic carbon analyser (DOC), 4) elucidating the structures of the transformation products (TPs) which formed during the degradation of TMI, DMI and CPTX by using LC-MS/MS analysis, 5) analysing the biodegradability of their TPs by laboratory tests and in-silico assessments in order to determine the fate and persistence of these TPs in the aquatic environment, 6) conducting in-silico toxicity predictions for the selected psychotropic drugs and their TPs in human (carcinogenicity, genotoxicity and mutagenicity) and in eco-system (toxicity to microorganisms and toxicity in rainbow trouts). As an overall conclusion, the present work demonstrates that a combination of laboratory simulation tests, LC-MS/MS analysis and in-silico tools result in valuable new information regarding environmental fate of three important psychotropic drugs and their TPs. This dissertation also highlights that different environmental conditions such as temperature, initial drug concentration and pH can differently affect the degradation behaviour of pharmaceuticals even when they are highly structurally related. Therefore, one cannot conclude from one pharmaceutical to another but each one needs to be investigated individually and this present a great challenge for risk assessment kinetics of chemicals in the aquatic environment. The results presented here showed that the investigated pharmaceuticals and their TPs can negatively affect the environment which may be harmful to the ecosystem as they might have been present for decades in the aquatic environment without any knowledge of their environmental fate or connected risk. Therefore, further work needs to be done including analysis of environmental samples (e.g., surface waters), as well as laboratory toxicity tests to further expand knowledge on their exact environmental impact.
Financial Decisions in Family Firms. Private Equity Investors, Capital Structures and Firm Identity
(2017)
This paper-based dissertation deals with financial issues of family businesses. These businesses are mainly characterized by the overlapping of the two social systems: family and business. Thus, the involvement of an owner family can have a significant impact on corporate decision-making, for instance in terms of corporate finance decisions. In Germany, the latter is dominated by a strong orientation towards banks. Nevertheless, the relevance of external equity, as source of funding, has increased during the last years due to regulatory interventions (Basel III) and a growing number of alternative private equity providers. Against this backdrop, the present dissertation and its four papers examine different research questions in the context of capital structure decisions of family firms. These decisions are related to external equity as well as debt financing. The first paper is a structured literature review concerning the interaction of family firms and external equity investors. The paper analyzes the current state of knowledge and points out directions for future research, which is particularly relevant for a young and recently growing field of research. The second paper is a conceptual paper that deals with the differences of various types of private equity investors from the perspective of family firms looking for funding. The literature review paper revealed that existing studies so far neglected the topic of heterogeneity among investor types. Thus, the second paper represents a first attempt to close this research gap. Paper three also takes up a research gap identified by the first paper and examines the exit of private equity minority investments in family-owned businesses. The paper applies a qualitative empirical research design, which includes fourteen cases and related six interviews. The results reveal that the disinvestment phase of private equity investors only rarely leads to conflicts with owner families. The fourth paper uses a quantitative research design with a comprehensive dataset of 691 companies. The paper aims to compare the capital structures of large family and non-family firms. Overall, the findings show that family firms have significantly higher overall and long-term debt levels compared to their non-family counterparts. The identity as a family firm, which leads to a leap of faith by banks, can be a possible explanation for these results.