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European species-rich grasslands are threatened both by land use intensification as well as land abandonment. The studies shown in this thesis tested the possible use of ecological knowledge to ensure hay productivity whilst maintaining diversity of grasslands, with a view to informing ecological restoration. The overall approach was to understand interactions between plants, to study diversity effects on productivity, and mainly investigate how plant functional groups that arrive first in the system can create priority effects that influence community productivity both above- and belowground. A grassland field experiment was established and monitored for four years, in order to verify the effects of manipulating the order of arrival of different plant functional groups, as well as the sown diversity level on productivity and methane yield. The overall findings were: a) sowing legumes first created priority effects aboveground (higher biomass) and belowground (lower root length), plants invested less in roots and more in shoots, b) priority effects were more consistent below than aboveground, c) sown diversity did not affect aboveground biomass, d) the order of arrival treatments indirectly affected methane yield by affecting the relative dominance of plant functional groups. Since the researchers lack information on how legumes and non-legumes interact spatially belowground, (particularly related to root foraging) a controlled experiment was performed, using two grass species and one legume. The identity and location of the neighbours played a role in interactions, and the order plants arrived modulated it. When the focal species (grass) was growing with a legume it generally equated to the same outcome as not having a neighbour. Roots from the focal species grew more toward the legume than the grass neighbour, indicating a spatial component of facilitation. Since these studies involved root measurements, a method study was also conducted to verify how comparable and accurate are root length estimates obtained from different techniques. Results showed that the use of different methods can lead to different results, the studied methods did not have the same accuracy, and the automated methods can underestimate the root length. Overall, the results allow to conclude that different groups of plants arriving before others affected above and belowground biomass, roots may be key drivers during the creation of these priority effects, and interaction outcomes between plants depended on neighbour identity and location, modulated by the order they arrive in. The results suggest that priority effects can be used by sowing different species or plant functional groups at different time to steer a community to a desired trajectory depending on the restoration goal. However, there is a need to test contingency, potential, and long term impacts of such possible tools for restoration.
This thesis aims at contributing to the better understanding of the roles of international and domestic institutional and governance patterns for corporate sustainability practices. By combining governance and new institutionalism approaches it bridges the gap between the close look at specific corporate sustainability (CS) policies and the broader view on institutional frameworks. The qualitative comparative approach aims to provide deeper insights on the implementation of different governance schemes by transnational corporations ((TNC). Finally, the conclusions might allow for the development of a) recommendations for the balancing of TNCs' CS management between global and domestic requirements, and b) policy recommendations in the field of CS governance. The overarching research question is as follows: What role do national governance patterns play in comparison to global governance practices in shaping the corporate sustainability (CS) management of transnational corporations (TNCs)? In order to further operationalize this research objective, it is structured into three subquestions: (1) What are relevant institutional factors and global governance patterns for corporate sustainability/ Corporate Social Responsibility (CSR)? (2) What are relevant institutional factors and national governance patterns for corporate sustainability/CSR in Germany, the US, and India? (3) How do these national and global governance patterns influence TNCs' CS management? The first two questions aim at tracing the institutional framework and governance patterns at both national and international levels by identifying norms, stakeholder expectations, prevalent modes of governance and actors involved in governance processes. On this basis, the third question targets TNCs' reaction to internationally varying governance patterns. Here, it is of main interest how relevant governance instruments are perceived by business actors and to which extent their sustainability management at the companies' headquarters and subsidiaries reflect global and national institutional and governance patterns. In order to answer these questions, literature research and a structured qualitative analysis have been conducted. The concepts of CS and CSR build the basis to analyze how TNCs and their subsidiaries manage their social and ecological corporate responsibilities. Against this conceptual background, the research question is approached empirically by the means of an international comparison. Three institutionally highly diverse countries were chosen: Germany, India and the US. India, an emerging market economy, was included to increase the diversity of the sample and to close the research gap indicated above. In order to identify the differences in governance for CS in these three countries, document analyses and 42 guideline-based interviews with experts from governments, NGOs, trade unions and trade associations were carried out. At the same time, global governance instruments for corporate sustainability – which are already relatively well researched - were identified by analyzing the relevant secondary literature. In a second step, in order to explore how TNCs strategically deal with the multitude of different governance approaches at their headquarters and subsidiaries, three case studies of Germany-headquartered transnational corporations in the chemical and engineering industries (Siemens, BASF and Bayer) have been conducted.
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.
Derivatives are contracts between two parties, a buyer and a seller. The contract will be fulfilled in some point in the future at a predetermined price. The value of those contracts is based on an underlying entity which can be a traded asset or even the weather. Derivatives contain chances, but also risks, investor should be aware off. This thesis aims to deeply analyze two derivative products in the German market and one risk for each which influences the prices of those products. The first part of this thesis focuses on warrants and the issuer's credit risk involved. It finds evidence that the issuer's credit risk influences the connection between warrant characteristic and its prices. Over time this connection is unstable partly driven by the issuer's credit risk. The second paper of this thesis shows that issuers seem to use their credit risk systematically to influence warrant prices. Evidence is found that the changes in credit risk are not fully included in the prices directly, but that the adjustment to the new level of credit risk takes several days. In addition, the issuer's adjustment to changes in credit risk are different for credit risk increases than for credit risk decreases. Especially after financial crisis, in more stable times, evidence is found for such adverse pricing pattern. The third part of the thesis focuses on energy derivatives traded at the Europe Energy Exchange and analyses the influence of weather parameters on energy derivatives with different load profiles and time horizons. This part of the thesis finds that especially wind speed and sun hours have a strong influence on energy derivatives. However, not all products are influenced in the same manner. Products with a longer time horizon are influenced less than the product with a short horizon. Moreover, products comprising hours of the day where energy consumption is expected to be higher are influenced stronger than products comprising hours of a day with lower time consumption. The thesis shows that derivatives are not alike and that it is needed for future research to differentiate between products and the risks which are involved. Since even though we classify them all as derivatives the risks influencing the derivative´s prices do vary tremendously.
Online advertising has become one of the most important dimension of corporate communications. In recent years, a new form of advertising on the Internet has emerged: real-time advertising. Among others, it allows companies to identify potential customers and target them with respect to their interests. In this way, real-time advertising can increase advertising effectiveness and it could, at the same time, improve user experience. With the emerge of this new form of advertising, statistical models have become even more important because they are now being increasingly used to predict online user behavior. The articles included in this dissertation analyze user-level clickstream data generated during multi-channel advertising campaigns (including TV advertising) and during real-time auctions. The goal of the analyses conducted here is to better understand advertising effects and to support decision-making in this context. Most of the analyses are based on Bayesian models. These models allow for a very flexible structure, which enables researchers to model, for instance, heterogeneity across different types of users or non-linear parameters such as users´ reaction times and exponential decay of advertising effects. In addition, these models allow for the inclusion of prior knowledge of parameter distributions, and, therefore, they are well suited for iterative analyses based on clickstream data. Bayesian models can be evaluated in different ways. Instead of only relying on statistical metrics, the articles included in this dissertation aim to estimate the economic value of these models based on their predictive performance. Although this measure can only approximate their true economic value, this approach can be used to compare and evaluate different models and to illustrate the impact of predictive analyses for companies in the context of big data. This dissertation contributes to both information systems research and marketing research and has many managerial implications. First, a process is developed to determine optimal sample sizes representing the best balance between computational costs and predictive accuracy in e-commerce in particular and big data contexts in general. In practice, this process can be used to reduce infrastructure and computational costs. Second, the articles included here describe models that can be used to measure the impact of television ads on users' online shopping behavior. The models can provide insights concerning the effectiveness of individual television ads, the interactions between different advertising channels and the difference in user behavior of TV-induced customers and their non-TV-induced counterparts. Thereby, the models could support decision-making with respect to future advertising campaigns and targeting. Third, the articles describe several possibilities to extend and improve decision support systems currently used in e-commerce and marketing. These improvements enable practitioners to predict users´ interests for arbitrary products and services by using corresponding websites as dependent variables. This approach can be used to improve the effectiveness of real-time advertising campaigns, especially those intended to raise brand awareness among customers.
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.
Members of Western organizations differ in various diversity attributes. In response, research aims to provide evidence-based recommendations on how to effectively manage diversity in teams. Within diversity research, the diversity faultlines approach has been particularly fruitful. It considers the impact of the alignment of multiple diversity attributes in teams. Strong diversity faultlines are associated with the emergence of relatively homogeneous subgroups in teams and have an overall negative impact on team processes and outcomes. This dissertation investigates factors that mitigate the detrimental consequences of strong diversity faultlines in teams, namely pro-diversity beliefs. It extends faultline literature beyond the conventional focus on processes and outcomes related to team members by emphasizing the leaders' perspective. The three empirical papers included in this dissertation systematically examine how strong pro-diversity beliefs can help unleashing the positive effects of team diversity despite strong faultlines. The first paper highlights the role of leaders' pro-diversity beliefs in mitigating the negative impact of diversity faultlines on two team processes: perceived cohesion and social loafing. Moreover, it compares the impact of socio-demographic faultlines (based on gender and age) and experience-based faultlines (based on team tenure and education level). Data was collected in a multisource field sample with 217 team members nested in 44 teams and the corresponding leaders. The second paper takes the impact of members' pro-diversity beliefs into account. It examines whether the impact of sociodemographic faultlines on performance is contingent on leaders' and members' pro-diversity beliefs. Moreover, the research group assumed that aggregate LMX would mediate this relationship. In a multisource data set obtained from 41 teams with 219 members and the corresponding leaders working for the German Ministry of Foreign Affairs, the investigators found partial support for their hypotheses. As expected, the impact of strong socio-demographic faultlines on diplomats' performance was least negative when both leaders and members held strong pro-diversity beliefs. The third paper zooms into processes and outcomes related to team leaders. It investigates how leaders' pro-diversity beliefs and their perceptions of members' prodiversity beliefs in teams with strong socio-demographic faultlines impact leaders´ task role assignment, performance expectation, and motivation. The research group conducted two experimental studies with students, one in Germany (N=55) and one in the US (N=134). Findings showed that strong pro-diversity beliefs held and perceived by leaders made them assign task roles that cross-cut rather than aligned with the subgroup structure created by faultlines. Moreover, leaders' perceptions of members' pro-diversity beliefs, but not their own beliefs, had a positive impact on their motivation, mediated by their performance expectation.
This work investigates how managers/consultants (practitioners) of different ranks are engaged in patterns of behavior (practices) in socially situated contexts (practice) attempting to shape preferred shared interpretations of reality to achieve their goals. Following this line of inquiry, the work aims at (1) advancing our understanding of the role of practitioners in shaping managerial realities and (2) investigating how practitioners actually shape managerial realities, particularly focusing on "reality-shaping" practices and their content. The dissertation comprises a set of four complementary articles investigating these research questions empirically based on in-depth, empirical case studies and theoretically within various managerial contexts (client-consultant relationship, CEO post-succession strategic change process, evolutionary initiative development) and considering different actor perspectives (top managers, middle managers, consultants and clients). Resulting from this variety, the articles rely on and contribute to different, at times distant, research fields and therewith scholarly discussions. However, the literature on sensemaking and sensegiving offers a suitable overarching theoretical frame which is used in this work to synthesize the key contributions of the four articles.
Wood-pastures have been present in Europe for thousands of years. This form of grazed landscape, combining herbaceous vegetation with trees and shrubs, has often co-evolved with its human users into complex social-ecological systems (SES). Wood-pastures are associated with high cultural and biodiversity values and are an example of the sustainable use of resources. However, due to their often relatively labour-intensive management and low productivity, large areas of wood-pastures have been lost over the last century. The loss of these areas means not only the loss of biodiversity on both local and landscape scales, but also the loss of traditional farming and cultural heritage in some regions. Across the European Union, wood-pastures are facing different problems and are embedded in different social systems and ecological environments. Yet they are all affected by global change and common European policies. To understand the challenges for wood-pastures in a changing world, a holistic approach combining different disciplines is needed. This dissertation therefore is analyzing wood-pastures across Europe as a Social-ecological System, combining ecology and social science with the aim to identify the barriers and drivers for wood-pastures persistence into the future.
Smartphones make intensive use of precious metals and so called conflict minerals in order to reach their high performance in a compact size. In recent times, sustainability challenges related to production, use and disposal of smartphones are increasingly a topic of public debate. Thus, established industry actors and newly emerging firms are driven to engage in more sustainable practices, such as sustainable sourcing of materials, maintenance services or take-back schemes for discarded mobile phones. Many of these latter efforts can be related to the concept of a circular economy (CE). This thesis explores how CE-related value creation architectures (VCAs) in the smartphone industry contribute to slowing and closing resource loops in a CE. In order to analyze these new industry arrangements, transaction cost theory (TCT) is used as a guiding theory for a make-or-buy analysis. Combining TCT with the concept of a CE is a novel research approach that enables the empirical analysis of relationships between focal actors (e.g. manufacturers) and newly emerging loop operators (e.g. recycling firms) in the smartphone industry. Case studies of such VCAs are conducted with case companies drawn from the Innovation Network on Sustainable Smartphones (INaS) at Leuphana Universtity of Lüneburg and analyzed regarding their involved actors, partnerships, circular activities, motivation and perceived barriers. Evidence from the conducted case studies suggests that asset specificity for circular practices increases for higher order CE-loops such as maintenance or reuse, therefore long-term partnerships between focal actors and loop operators or vertical integration of CE practices are beneficial strategies to reach a sophisticated CE. Similarly, circular practices that go beyond recycling require a strong motivation, either through integration in the focal firm´s quality commitment or through business model recognition. It is further suggested that the circular design of products and services could reduce necessary transaction costs and thus overall costs of a circular economy. Four different integration strategies for circular economy practices have been derived from the conducted case studies. These are: 1) vertically integrated loops, 2) cooperative loop-networks, 3) outsourcing to loop operators and 4) independent loop operators. This work thus provides evidence that circular economy activities do not necessarily have to be managed by focal actors in the value chain. Rather, circular practices can also be put forward by specialized loop operators or even independent actors such as repair shops.