Open Access

Does the presentation of travel experience affect personal prestige of tourists? Prestige enhancement has been considered a motive for travel by tourism researchers for decades. Yet, the question whether representation of travel experience actually leads to personal prestige enhancement has been widely neglected so far. The study of prestige benefits of travel is a necessary endeavour to develop suitable methodological approaches toward the concept, in order to close critical knowledge gaps and enhance scientific understanding. The present thesis lays out the rationale and results of three research projects which shed light onto the relationship between touristic self-presentation and its effects on personal prestige evaluations of the social environment. The empirical studies conducted in the frame of this dissertation conclude in the following main findings: Leisure travel is a useful means for people to self-express in a positive way, and material representations of travel are frequently displayed to others. Tourists make use of travel experience to self-present in a positive way by uploading photos on social media, collecting and displaying souvenirs, wearing jewellery and clothing from their last trip, or talking about their trips to others. They express positive self-messages about personal character traits, affiliation to social in-groups and proof of having travelled somewhere. The findings ascertain the utility of travel representations for positive self-expression, showing that travel experience is an effective vehicle for conspicuous consumption and self-expression as an antecedent for personal prestige enhancement. Personal prestige is an element of social relations, and holds capacity to affect perceptions of social inclusion and social distinction, so it has to be conceptualised as a multidimensional construct. In a tourism context, personal prestige is reliably measurable along the four dimensions of hedonism, social inclusion, social distinction and prosperity. The herein developed Personal Prestige Inventory (PPI) is a valid, reliable and parsimonious measurement tool which substantially enhances methodological approaches toward empirical research into personal prestige. The way in which people represent travel experience to others measurably affects how their personal prestige is evaluated by social others. Empirical evidence of a series of experimental studies provides support for the assumption that representation of travel experience has an effect on the social evaluation of tourists’ personal prestige. Experimental variance suggests small to moderate effects on personal prestige depending on the amount of leisure information given about a person, participation in tourism, and the destination and type of travel represented. This evidence is reasonable basis to conclude that whether and how people travel, and whether and how they share travel experience with others, does measurably affect social other’s evaluation of their personal prestige. By providing qualitative evidence for positive self-presentation through leisure travel, and the subsequent development and experimental application of the Personal Prestige Inventory (PPI) in a tourism context, the present dissertation enhances scientific understanding of personal prestige in the context of leisure travel and provides useful methodological advancements for further research into the topic.

The academic literature holds high expectations of crowdfunding to foster sustainable development by closing the funding gap for sustainable entrepreneurs. In particular, 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. Large knowledge gaps exist especially in the area of investment-based crowdfunding. 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 findings also suggest that the typical supporter of sustainability-oriented crowdfunding projects is younger than 50 years, has achieved at least a university degree and holds low levels of self-enhancement and conservative values. 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.

Who is taken into consideration when we talk about the citizens, about the people or the activists? Often it is a rather unquestioned privileged positionality, which is taken to be the standard that most of the time it is actually not. In this quote, the activist Madjiguène Cissé, from the transnational Sans-Papiers movement, raises that just because someone or something is not visible—to the broader public or a particular public—it does not mean that they have not been there for a long time. Migrant rights activism is not a new phenomenon but has intensified and become more networked and visible over the past years (Eggert & Giugni, 2015). This study explores group contexts of activism by, with and for refugees and migrants in Hamburg, the claims, interactions, challenges and processes that activists experience, discuss and deal with. I have approached activists experiencing political organizing in this context from a constructivist grounded theory perspective. This allowed me to develop conceptual perspectives grounded in activist groups’ realities and was advanced through existing literature on this social movement but also theories from other research fields. Solidarities emerged throughout the research process as a more concrete focus. This research sets out to answer the questions: What does solidarity mean in social movements, and how do migrant rights activist practices result in negotiating, enacting and challenging it? This publication is a revised version of my dissertation thesis.

In political and academic debates, there are increasing voices for a sustainable transformation that culminates in the demand for collaborative human action. Collaborative governance is a promising approach to address the difficult challenges of sustainability through global public and private partnerships between diverse actors of state, market and civil society. The textile and clothing industry (hereafter: textile sector) is an excellent example where a variety of such initiatives have evolved to address the wicked sustainability challenges. However, the question arises whether collaborative governance actually leads to transformation, also because the textile sector still faces various sustainability challenges such as the violation of workers' rights, agriculture and water pollution from toxic chemicals, and emissions from logistics that contribute significantly to climate change. In this dissertation, I therefore question whether and how collaborative governance in the textile sector provides space for, or pathways to, sustainability transformation. In three scientific articles and this framework paper, I use a mixed-methods research approach and follow scholars of sustainability science towards transformation research. First, I conduct a systematic literature review on inter-organizational and governance partnerships before diving into a critical case study on an interactive collaborative governance initiative, the German Partnership for Sustainable Textiles (hereafter: Textiles Partnership). The multi-stakeholder initiative (MSIs) was initiated by the German government in 2015 and brings together more than 130 organizations and companies from seven stakeholder groups. It aims at improving working conditions and reducing environmental impacts in global textile and clothing supply chains. In two empirical articles, I then explore learning spaces in the partnership and the ways in which governance actors navigate the complex governance landscape. For the former, I use a quantitative and qualitative social network analysis based on annual reports and qualitative interviews with diverse actors from the partnership. Then, I use qualitative content analysis of the interviews, policy documents and conduct a focus group discussion to validate assumptions about the broader empirical governance landscape and the social interactions within. Finally, in this framework paper, I use theories of transformation to distinguish forms of change and personal, political and practical spheres of transformation, and reflect on the findings of the three articles in this cumulative dissertation. I argue that collaborative governance in general and MSIs in particular provide spaces for actors to negotiate their diverse interests, values and worldviews, which is a valuable contribution to social learning and interaction for transformation. However, private governance structures and the diversity and unharmonized nature of initiatives in the landscape hinder the realization of the full potential of such partnerships for practical transformation. My case study shows that in such partnerships, structures emerge that impede the full engagement of all actors in constructive conflict for social learning because they create structures in which few are actively involved in making decisions. This traces back to a practical trade-off between learning and achieving governance outcomes. I argue that decisions should not be rushed, but space should be provided for the confrontation of different values and interests to arrive at informed solutions. Additionally, actors in such partnerships are completely overwhelmed by the multiplicity of different and mostly voluntary initiatives and partnerships, which bring different, non-harmonized commitments, so that actors take on varying and sometimes conflicting roles. MSIs are thus limited by the need for stronger state regulation, which in Germany is now leading to the implementation of the Due Diligence Act in June 2021. Collaborative governance initiatives are thus critical platforms where different actors are able to negotiate their values and political interests. However, they need to be embedded in governmental framework conditions and binding laws that transcend national borders, because the industry's challenges also transcend borders. Only in this way can they contribute substantively to transformation. Further research should focus on the interplay between state and private regulation through further case studies in different sectors and foster inter- and transdisciplinary research that allow for spaces for social interaction and learning between science and practice.

Considering the recent success of right-wing populist candidates and parties in the United States and across Europe, there has for some years now been talk among scholars (and the wider public) about a worldwide democratic recession. Levitsky and Ziblatt paint a very gloomy picture when they write that democracy is at risk of dying. Others are not as pessimistic, but they still argue that democracy is in a state of serious disrepair. The younger generations appear to be especially unsupportive of democracy’s liberal principles and more willing to express support for authoritarian alternatives. What these authors overlook, however, is that the publics of advanced industrial societies have experienced an intergenerational value shift. In fact, populations in industrial democracies have become more liberal overall, but not everyone’s mindset is changing at the same speed. It is mainly – but not exclusively – the members of the lower classes that do not keep up. While societies have generally become more liberal, there is increasing alienation between the social classes over these liberal values. Drawing on a more recent trend in social class research with a social cognitive approach, this dissertation contributes to the study of growing anti-democratic tendencies around the world by analyzing the interplay between inequality dynamics and value orientations. The focus lies on investigating the effect socio-cultural polarization (i.e., ideological polarization between social classes) has on civic culture in the mature democracies of the West. The findings suggest that it is not ideological polarization between the social classes that has the greatest negative effect on civic culture, or general civic attitudes and behavior, for that matter. It is the increasing dissent in society about whether the country’s elites are still to be trusted with making the right decisions to increase the average citizen’s quality of life. This difference in opinion manifests itself in a decline in some civic attitudes.

The transition of our energy system towards a generation by renewables, and the corresponding developments of wind power technology enlarge the requirements that must be met by a wind turbine control scheme. Within this thesis, the role of modern, model-based control approaches in providing an answer to present and future challenges faced by wind energy conversion systems is discussed. While many different control loops shape the power system in general, and the energy conversion process from the wind to the electrical grid specifically, this work addresses the problem of power output regulation of an individual turbine. To this end, the considered control task focuses on the operation of the turbine on the nonlinear power conversion curve, which is dictated by the aerodynamic interaction of the wind turbine structure and the current inflow. To enable a power tracking functionality, and thereby account for requirements of the electrical grid instead of operating the turbine at maximum efficiency constantly, an extended operational range is explicitly considered in the implemented control scheme. This allows for an adjustment of the produced power depending on the current state of the electrical grid and is one component in constructing a reliable and stable power system based on renewable generation. To account for the nonlinear dynamics involved, a linear matrix inequalities approach to control based on Takagi-Sugeno modeling is investigated. This structure is capable of integrating several degrees of freedom into an automated control design, where, additionally to stability, performance constraints are integrated into the design to account for the sensitive dynamical behavior of turbines in operation and the loading experienced by the turbine components. For this purpose, a disturbance observer is designed that provides an estimate of the current effective wind speed from the evolution of the measurements. This information is used to adjust the control scheme to the varying operating points and dynamics. Using this controller, a detailed simulation study is performed that illustrates the experienced loading of the turbine structure due to a dynamic variation of the power output. It is found that a dedicated controller allows wind turbines to provide such functionality. Additionally to the conducted simulations, the control scheme is validated experimentally. For this purpose, a fully controllable wind turbine is operated in a wind tunnel setup that is capable of generating reproducible wind conditions, including turbulence, in a wide operational range. This allows for an assessment of the power tracking performance enforced by the controller and analysis of the wind speed estimation error with the uncertainties present in the physical application. The controller showed to operate the turbine smoothly in all considered operating scenarios, while the implementation in the real-time environment revealed no limitations in the application of the approach within the experiments. Hence, the high flexibility in adjusting the turbine operating trajectories and structural design characteristics within the model-based design allows for efficient controller synthesis for wind turbines with increasing functionality and complexity.

Increasing objections have been formulated towards broadening the security category. Securitisation is used to bring attention to urgent and existential threats that cannot be resolved through ordinary political decisions. During the time of the state of emergency between 2015 and 2017, France strengthened its security forces and introduced generalised surveillance measures to curb the terrorist threat. The purpose of this Bachelor thesis is to problematise the securitisation of terrorism in the French case. To do so, the Just Securitisation Theory by Rita Floyd is used to examine the following research question: Was it just to securitise terrorism in France between 2015 and 2017? Through critical discourse analysis of 54 presidential speech acts and secondary text analysis, this study aims to scrutinise securitising moves and security practices of the French government. The presented results indicate that the justness of securitisation is highly questionable. The analysis shows that the governments set excessive goals of eliminating terrorism and that security measures were misappropriated to fight organised crime instead of terrorism. Keywords: Securitisation; Counterterrorism; France; Just Securitisation Theory; Critical Discourse Analysis

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, as on the one hand it influences the growth of biomass and therefore the grazing intensity, but on the other hand it can also destroy entire herds through extreme climatic events. Rangeland systems are seriously threatened by climate change, because climate change will alternate the availability of water in time and space. This is dangerous in that we have not yet fully understood how grazing affects vegetation under different climatic conditions. Inadequate rangeland management can quickly lead to serious degradation of the grazing grounds. 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 (100 mm annual precipitation), and comparatively high precipitation and low climatic variability in the north (250 mm). 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 10 m x 10 m 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, we 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, I conclude 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 fate of Mongolia’s rangeland systems therefore clearly lies in the hand of the rangeland managers. The sustainable use of Mongolia’s vast steppe ecosystems might depend on a flexible livestock management system which balances the grazing intensity with the available resources, while still considering climatic variability as a key for the management decisions. A potential link-up for future studies might arise from the shortcomings of the studies presented. This dissertation suggests that long-term observations are necessary to better understand the effects of climatic variability. In addition, grazing gradients must be selected more carefully in the future in order to be able to ensure better comparability, and functional analyses should have a stronger relationship to forage quality. With these points in mind, a comparative study of several rangeland ecosystems on a global level must be the ultimate goal. This could be an important step for the sustainable use of drylands in the context of global climate and land use change.

Transformative learning is increasingly set to become an essential component in sustainability transformation. This type of learning attracts considerable interest in studying and impulsing a paradigm change to transform our world into a more sustainable one, yet its underlying learning mechanisms have remained overlooked. Although there is an apparent relationship between transformative learning and sustainability transformation, little has been done to systematically explore the contribution to sustainability transformation. This learning theory developed decades ago independently of sustainability discourses; however, it provides an analytical framework for understanding the learning processes, outcomes and conditions in individual and social learning towards sustainability transformation. Against this background, the following research question arises: To which extent can transformative learning lead to sustainability transformation? This doctoral work aims to explore transformative learning processes, outcomes, and conditions occurring and advancing towards sustainability transformation of the textile-fashion industry in Mexico. Taking an exploratory approach, the methods employed were literature reviews to untangle concepts and to construct theoretical pillars to support the empirical research design and data analysis. For data collection, snowball-sampling techniques were used to explore the practice field of the textile-fashion industry in Mexico. Qualitative interviews were employed to gather data about the learning experiences of actors. Qualitative and quantitative methods were required to perform the respective data analysis, the qualitative codification of interviewees’ responses through MAXQDA being the most remarkable one. Analysis of social media content was also utilised to understand the communication and business practices of projects involved in the transformation of the textile-fashion sector. As a result, this work comprises three articles, one a systematic literature review and two empirical research articles, investigating the transformative learning processes of entrepreneurs in the development of sustainability niches. As for the findings of this doctoral work, the use of transformative learning in sustainability transformation requires a careful study of the theory and its conceptual elements. Regarding the case study, transformative learning is inherent in forming and developing sustainability niches as entrepreneurs venture into them: It is individual prior learning, expectations and actions that initiate the path of sustainability transformation while disorienting dilemmas, critical reflection, and discourse accelerate them. Through these stages, it is when individual learning turns into social learning. On the other hand, based on the multi-level perspective, the interplay between the niche, regime and landscape levels generates a space for sustainability transformation and transformative learning. This work contributes to deciphering the black box of learning in sustainability transformations. The principal endeavour was to build the theoretical bridges between this emerging area of inquiry and transformative learning theory, as a significant part of this theoretical construction required drawing upon other research fields such as sustainability transitions and sustainability entrepreneurship. The crosscutting feature of learning in those fields enabled the development of an awareness of boundary objects between those fields (e.g., expectations). Furthermore, this study is pioneering in exploring sustainability transformation processes of the textile-fashion industry in Latin American contexts. The findings of this work can also be extrapolated to other sectors in which entrepreneurs participate, such as local food production, sustainable mobility, among others

Corporate Social Responsibility (CSR) has been established in recent years as an essential component of the economic system, demanded and promoted by a wide variety of stakeholder groups. The present dissertation shows that organizations face major communicative challenges with regard to CSR. CSR is not only determined by organizations themselves, but rather arises in the interplay with economic and social discourses. It is assumed that boundarys of organizational action are under constant change, so that CSR actors inevitably initiate constitutive communication processes. The resulting polyphony requires an understanding of the underlying communication processes. Hence, the performative character of CSR communication is taken up by this dissertation and thus the constitution of both the communicating actors and their relationships in the network is illustrated. The presented scientific papers are united by the overarching assumption that communication does not accompany and describe organizational action, but unfolds its own power.

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, where the works related to the analyzes of the impact of radial clearance on the dynamics of rolling bearings have been cited so far. 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.

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. We first focus on computing representative subsets for a matrix factorization technique called archetypal analysis and the setting of optimal experimental design. For these problems, we motivate and investigate the usability of the data boundary as a representative subset. We also present novel methods to efficiently compute the data boundary, even in kernel-induced feature spaces. Based on the coreset principle, we 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, we are concerned with efficient data representations for density estimation. We 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, we highlight issues of interpolating data in normalizing flows, a technique that changes the representation of data to follow a specific distribution. We show how to solve this issue and obtain more natural transitions on the example of image data.

Increased international compliance with human rights and democracy standards is a core issue for both human rights and democratizing actors as well as for victims of human rights abuse. International human rights organizations (IHROs) are expected to make positive contributions to this end, even though they possess low levels of authority. This authority has been renegotiated multiple times in various reform processes. An oversimplified expectation would have us assume that democracies would want to strengthen IHROs, and that autocracies would seek to weaken them. As the United Nations Human Rights Council (UNHRC) was reformed in 2006, 2007, 2010, and 2011, some autocracies strived to abolish parts of the UNHRC. Other autocracies aimed “merely” to weaken them. Democracies displayed an even larger variance. Indonesia and India predominantly favored weakening the UNHRC, whereas Ghana and Spain supported exclusively strengthening of the organization. Additionally, some attitudes towards the UNHRC changed from one year to the next. Autocracies diverge not only in their stances towards the UNHRC, but also across their domestic and international dimensions. Nigeria allows different levels of participation by societal actors than, say, Belarus. Cuba does not have the same domestic institutions as Russia. Iran enters international negotiations from a different position than Thailand. Democracies vary on the domestic and international dimensions as well. The Czech Republic is not the US, and Costa Rica is different from South Africa. The question that drives my research is how we can explain the broad variety of state preferences for strengthening or weakening IHROs. Previous research has mostly concentrated on democracies, leaving autocracies understudied. It also treated countries as black boxes. To account for such shortcomings, first, I systematically test the relationship between the UNHRC and its authoritarian and democratic members by means of inferential statistics. Second, I analyze a bottom-up process inherent to New Liberalism. It scrutinizes the role of domestic societal actors, domestic institutions, as well as pressures on the international stage. The results reveal that societal actors, along with the interplay of wealth and regime type in the international realm, figure as the most important predictors of delegation preferences voiced by autocracies and democracies during the reform of the monitoring bureaucracy Special Procedures of the UNHRC. Societal actors play a more important role in democracies than in autocracies. Institutionalized domestic oversight mechanisms help societal actors to conduct effective lobbying at the domestic level. Oversight mechanisms are more important than the rule of law and electoral institutions. Regarding international coalition building, authoritarian regimes turn out to be better organized than democracies. I conclude that supporters of strong IHROs shall 1. empower domestic societal actors; 2. disrupt cohesive delegation preferences of authoritarian regimes; and 3. invest in independent domestic oversight mechanisms.

The choice to continue working until or even beyond retirement is a function of the interplay of factors on micro, meso, and macro levels. Research within this area has grown significantly over the last years. I contribute to this line of research with the studies conducted within the scope of this cumulative habilitation thesis. More specifically, the aim of the research presented here is to add to the literature on later life work with the investigation of individual (micro level) as well as job and organizational (meso level) factors that have the potential to contribute to prolonged working lives. I was guided by the general research interest on how individual, job, and organizational factors contribute to later life work, and more specifically to retirement timing and work-related activities beyond normal retirement age. My research was directed by the following research questions: (1) What is the work activity potential of older people in Germany and what characterizes different types of later life work potential? (2) Which role do individual psychological factors such as personality, values, and beliefs play in the context of later life work? (3) How do specific job characteristics interact or align with individual psychological factors with regard to later life work? (4) What characterizes a holistic organizational approach to later life work that helps the alignment of the work environment to older workers’ (individual) needs and abilities? Following an introduction, I give an overview on the theoretical framework of my research in Chapter 2 (“Theoretical Background”). I describe the conceptualization of later life work before I go into multilevel antecedents of later life work and present key theoretical approaches to a person-environment fit perspective of later life work. In the following four chapters, I present ten studies corresponding to the ten scientific publications that constitute the basis of the cumulative habilitation thesis. In Chapter 3 (“Later Life Work: Work Activity Potential”) I present research on the extent as well as different types of later life work potential in Germany to describe the context for most of my research. With the two studies presented here (Büsch, Zohr, Brusch, Deller, Schermuly, Stamov-Roßnagel, & Wöhrmann, 2015; Mergenthaler, Wöhrmann, & Staudinger; 2015), I also intend to provide answers to the research question on the later life work potential in Germany and the characteristics of different later life work potential constellations. In Chapter 4 (“Later Life Work: Individual Psychological Factors”) the role of stable as well as malleable individual psychological factors for later life work is explored in two studies (Fasbender, Wöhrmann, Wang, & Klehe, 2019; Wöhrmann, Fasbender, & Deller, 2016). Thus, with the studies presented in this chapter, I contribute to the research question on the role of individual psychological factors in the context of later life work. In Chapter 5 (“Later Life Work: Job Characteristics Corresponding to Older Workers’ Needs and Abilities”) I present three studies exploring the interplay of individual factors and job characteristics for later life work to address the research question on the interaction or alignment of specific job characteristics with individual psychological factors with regard to later life work (Pundt, Wöhrmann, Deller, & Shultz, 2015; Wöhrmann, Brauner, & Michel, 2020; Wöhrmann, Fasbender, & Deller; 2017). Chapter 6 (“Later Life Work: A Holistic Organizational Approach”) reports the development of the Later Life Workplace Index (LLWI) as a multidimensional tool to holistically assess organizational practices and working conditions targeted at the promotion of later life work through the maintenance and enhancement of older employees’ health, work ability, and motivation (Wilckens, Wöhrmann, Adams, Deller, & Finkelstein, 2020; Wilckens, Wöhrmann, Deller, & Wang, 2020; Wöhrmann, Pundt, & Deller, 2018. With the LLWI, I intend to provide an answer to the research question on the characteristics of a holistic organizational approach to later life work that helps the alignment of the work environment to older workers’ (individual) needs and abilities. Finally, in Chapter 7 (“General Discussion”) I discuss the contributions, implications, and limitations of my research presented here.

Consisting of three articles and a framework manuscript, this cumulative dissertation deals with sustainable compensation of chief executive officer (CEO) with a focus on climate-related aspects. Against the backdrop of the European action for sustainability and the EU Green Deal, the dissertation pays special attention to the consideration of climate-related aspects of corporate performance in CEO compensation. In this context, sustainable compensation is characterized by the consideration of long-term interests and sustainability of the company as well as by the inclusion of financial and non-financial aspects of environmental, social and governance performance (ESG) in compensation agreements. While this novel instrument of corporate governance aims to incentivize the implementation of sustainability-oriented corporate strategy, it is particularly important to unfold this incentive effect at the individual CEO level in view of their managerial discretion. The framework manuscript discusses the research objectives, the regulatory and theoretical background, the results of the dissertation and their implications in the context of regulation, research, and business practice. The essence of the dissertation are the three articles. The first article, "Determinants and effects of sustainable CEO compensation: a structured literature review of empirical evidence," examines the current state of empirical research based on 37 articles that were published between 1992 and 2018. Based on a multidimensional research framework, the structured literature review compiles past research findings, identifies contentual and methodological foci in the research area, and derives questions for future research. The second article, "Mapping the determinants of carbon-related CEO compensation: a multidimensional approach," addresses the topic from a conceptual perspective. Taking the existing work as a starting point, a conceptual framework is derived, which organizes the determinants of carbon-related CEO compensation at societal, organizational, group and individual levels of analysis. On this basis, eight propositions are presented that seek to distinguish between the determinants which support and challenge the implementation of carbon-related CEO compensation. The third article, "Climate change policies and carbon-related CEO compensation systems: an exploratory study of European companies," focuses on the use of CO2-oriented performance indicators in CEO compensation. The empirical-qualitative study analyzes corporate disclosure of the 65 largest companies in the EU for the years 2018 and 2019. The study addresses the use of CO2-oriented performance indicators in corporate strategy and CEO compensation. It also examines which compensation components are determined with the help of CO2-oriented performance indicators, which type of performance indicators are used, and whether CO2-intensive and less CO2-intensive companies differ in this regard.

Understanding that entrepreneurship can be better modeled from a systemic point of view is a primordial aspect that determines the important role of universities in entrepreneurial ecosystems. What makes the ecosystem approach a valuable tool for understanding social systems is that, from a holistic perspective, their behavior seems to have emerging characteristics. The impact of this “research object” can only be revealed through interrelated causal chains similar to the behavior of natural ecosystems (Mars et al., 2012). Therefore, the entrepreneurial ecosystem concept provides a unique perspective that complements previous studies on networked economic activity with a clear focus on the systemic elements that support entrepreneurship, and an emphasis on policy that promote the entrepreneurial process. This dissertation presents a dual scientific account of the entrepreneurship phenomenon in universities. The work is divided into two equal parts, each of which is composed of two research papers. The narrative of the first half takes on a macro perspective view, consisting of one theoretical and one empirically-based conceptual case study. This part conceptually depicts a systematic approach to entrepreneurialism in higher education, namely an ecosystems perspective. The second half concentrates on the meso- and micro levels of study from the university’s point of view, comprising of a case study as historical account for the emergence of the entrepreneurial university, and of a metasynthesis of empirical case studies in entrepreneurial universities, which serves as the basis for the development of entrepreneurial university archetypes. This doctoral work contributes to an in-depth understanding of Entrepreneurship in universities regarding its systemic qualities and archetypal characteristics of entrepreneurial universities. It argues for an ecosystem’s perspective on the phenomenon of entrepreneurial activity, highlighting the fundamental role that universities play as the heart of entrepreneurial ecosystems. Furthermore, this research expands on the novel concept of the entrepreneurial university by using extensive case study literature to empirically identify distinct archetypes that better reflect the diverse reality of how universities engage as entrepreneurial actors by way of differentiated entrepreneurial structures, systems, and strategies.

Companies increasingly use social and environmental accounting and reporting (SEAR) to measure, manage, and report their influence on ecological and social issues, i.e., climate change and human rights violations. One reason for the increased use of SEAR is that companies aim to support sustainable aspects in their business decision-making. Nowadays, there are many different tools, frameworks, and standards for SEAR that companies can use. Beyond the content presented in the tool itself, e.g., social and/or ecological information, these tools differ, among others, by the language used and the type of data collected (e.g., qualitative, quantitative, or monetary data). One the one hand, the range of different approaches for SEAR allows industry- and company-specific monitoring and reporting of sustainable issues. On the other hand, this variety as well as the lack of a common reference framework can lead to uncertainty of corporate decision-makers and stakeholders regarding the use and comparability of these approaches. While numerous previous scholars present advantages and opportunities of the use of SEAR for companies and society, there is a rising number of scholars criticizing the way (social and environmental) accounting and reporting is used today and its impact on a company’s environmental orientation and decision-making. Further, there is only limited literature on the question of which approach to use and how to use and introduce the particular approach for supporting sustainable decision-making within companies. This dissertation aims to expand previous literature by clarifying the effects of SEAR on corporate decision-making and its influencing factors. Additionally, antecedents for implementation and use of SEAR in regard to supporting sustainability decision-making are discussed. For this purpose, the given dissertation investigates public sustainability reports by companies with different environmental orientation, conducts two survey-based case studies on the effects of different types of SEAR and one qualitative case study on the antecedents of institutionalizing management accounting change through SEAR. The results lead to seven criteria that practitioners and researchers should recognize for supporting successful SEAR regarding a company’s environmental orientation, the role of employees and leadership as well as the specific SEAR tool itself. Additionally, this dissertation leads to several contributions to the scientific discussion and its influences on corporate environmental orientation and decision-making.

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.

Global environmental changes and the subsequent biodiversity loss has raised concerns over the consequences for the functioning of ecosystems and human well-being. This thesis provides new mechanistic insights into the role of tree diversity in regulating forest productivity and forests’ responses to climate change. The thesis also addresses the overlooked functional role of ecological continuity in mediating ecosystem processes in the context of multiple global environmental changes. The findings of the thesis emphasize the need to retain the functional integrity of forest ecosystem by preserving biodiversity and acknowledging the ecological memory forests.

This cumulative dissertation investigates food policy councils (FPCs) as potential levers for sustainability transformation. The four research papers included here on this recent phenomenon in Germany present new insights regarding the process of FPCs’ emergence (Emergence paper), the legal conditions which affect their establishment (Legal paper), the different roles of FPCs in policy-making processes (Roles paper) and FPCs’ potential to democratise the food system (Food democracy paper). Drawing on and contextualizing the results of the four individual studies, the framework paper uses the leverage points concept originally developed by Meadows (1999) and adopted by Abson et al. (2016) as a lens to discuss FPCs’ potential as levers for sustainability transformation. This conceptual background includes three so-called realms of leverage, which are considered to be of particular importance in transformational, solution-oriented sustainability science: first, the change, stability and learning in institutions (re-structure), second, the interactions between people and nature (re-connect) and third, the ways in which knowledge is produced and used (re-think). Framing the findings of the four research papers in terms of these three realms, the framework paper shows that FPCs could serve as cross realm levers, i.e. as interventions that simultaneously address knowledge production, institutional reform and human-nature interactions.

This dissertation, entitled “How to Embed Sustainability in the Core of Higher Education Institutions: Drivers of, Barriers to, & Patterns behind the Implementation Processes of Sustainability Curricula – Insights from a Quantitative Meta-Study with Data from around the Globe,” addresses the question of how sustainability curricula1 can be implemented and established in higher education institutions2. This research question is based on the assumption that sustainable development requires new ways of thinking and acting in the world. Accordingly, universities – as hubs for knowledge generation, innovation, and education – provide a central leverage point for sustainably developing society at large. Therefore, the institutionalization of sustainability curricula is not only socially demanded, but also stipulated in numerous political statements from the international community (e.g., those of the UN and UNESCO) and operationalized via Sustainable Development Goal No. 4: “Quality Education”. Previous findings on how such implementation can be successful and what factors support or inhibit the process have come primarily through case studies of individual higher education institutions. These studies provide important insights but have been largely descriptive rather than analytical and leave open questions about the generalizability of their findings – for example, the extent to which other universities can be guided by the experiences of the respective higher education institutions. The present dissertation addresses this research gap. Through a meta-study (i.e., an analytical comparison of existing case studies), generalizable findings on the implementation processes of sustainability curricula are explored. In the first step, a case universe was collected in order to provide a database for deeper analyses. In two further analysis steps that built on the case universe from Step 1, certain factors that promote or inhibit the implementation of sustainability curricula (Step 2) and specific implementation patterns (Step 3) were examined. The following paragraphs provide greater details and an overview of the respective findings. In the first step, a database of peer-reviewed English-language case studies from around the globe that report on such processes was created. A total of 230 case studies were identified, 133 of which focus on the implementation processes of sustainability curricula.3 A bibliometric analysis of the 230 case studies revealed that this field of research is growing, although the discourse is primarily dominated by authors from North America, Europe, Oceania, and Asia, with South America and Africa being underrepresented. In addition, a citation analysis demonstrated that some universities incorporate findings from other countries whereas other universities act in isolation. This observation leaves open the question of the extent to which universities learn from one another in order to advance the implementation of sustainability curricula. In the second step of the analysis, the qualitative data of the collected case studies (sample of 133 case studies) were compared using the case survey method, which is a specific type of a meta-1 Sustainability curricula include courses, programs, and certificates from all fields of study that deal in some form with sustainability topics. For a more-detailed discussion of what education for sustainable development (ESD) entails, see Section Error! Reference source not found.. 2 Higher education institutions (HEIs) include universities, universities of applied sciences, and other institutions that offer at least a bachelor’s degree. 3 A detailed explanation of the case sample and subsamples can be found in Section Error! Reference source not found.. analysis. The focus of the comparison lay on the drivers of and barriers to the processes of sustainability curriculum implementation at higher education institutions. Driving- and inhibiting factors have been thoroughly examined theoretically in the discourse on education for sustainable development (ESD), especially those pertaining to higher education institutions. However, no large body of data has yet been created to empirically test these hypotheses. The present meta-study found that the following factors lead to the deep-rooted and comprehensive establishment of sustainability curricula: strong leadership support; the establishment of sustainability curricula in the areas of education, research, campus operations, and outreach activities; formal participation of internal (including students) and external stakeholders; and engagement by sustainability champions (change agents), who are often the first to implement sustainability curricula and can face strong resistance. Other enabling factors include strategic planning, coordination, communication, having a vision, external political influence, the presence of a window of opportunity (e.g., an environmental disaster, a change in presidency), and the availability of interdisciplinary meeting spaces. On the other hand, the strongest cited barriers to the implantation of sustainability curricula were found to be the lack of interdisciplinary meeting spaces, the lack of a vision, the lack of incentives, the lack of resources, an overly full curriculum, and an unsupportive / overly bureaucratic organizational structure. The third step of the analysis also built on data from the 133 case studies and explored whether certain types or patterns of implementation processes occur. Through the analysis, six implementation patterns were identified that share similar driving- and inhibiting factors. The respective interplay between factors leads to various degrees of sustainability curriculum implementation in terms of how deeply rooted and comprehensive this implementation is. As discussed in greater detail below, in descending order of the level of achieved deep-rooted change, these patterns are (1) a collaborative paradigm shift, (2) bottom-up institutional change, (3) top-down institutional change, (4) the presence of many barriers that hinder institutional change, (5) externally driven initiatives, and (6) initiatives that are scattered due to a lack of coordination. Across all patterns, two phases could be identified: First, the impetus to implement ESD may be initiated not only by internal actors, but also by external ones. This initiation can take hold from the “bottom-up” (i.e., by students or faculty), from the “top-down” (i.e., at the presidential level), or in both directions simultaneously. The following key factors appear to be important in driving the initial implementation forward: a culture of open communication between all stakeholders in which feedback and reflection are welcome and even actively solicited, the development of a shared understanding and vision that further create a sense of ownership and long-term success, a high level of collaboration among all stakeholders, and existing initiatives that lead to knowledge sharing and other resources. In this regard, informal collaboration and cooperation can partially compensate for a lack of presidential-level support and/or a formal communication structure. Furthermore, developing a strategy with individual steps and shared responsibility leads to more-successful implementation of ESD at higher education institutions. The presented findings add a complementary empirical perspective to the discourse on the establishment of ESD at higher education institutions. First, the case studies that specifically address the implementation processes of sustainability curricula are reviewed and analyzed here for the first time as part of a research landscape. This research landscape reveals where research on such implementation processes has been or is being conducted. On this basis, both researchers and funders can reflect on the status quo and plan further research- or funding endeavors. Second, this dissertation offers the opportunity to compare a multitude of individual case studies and thus to develop new and generalizable insights into the implementation of sustainability curricula. The empirical analysis uses 133 case studies to identify key factors that promote or inhibit the implementation of sustainability curricula and to add a complementary perspective to the discourse, which has thus far been dominated by theoretical considerations and individual case studies. The analysis thereby offers a new perspective on generalizable influencing factors that appear to be important across different contexts. Thus far, specific patterns of implementation processes have been infrequently studied, and with few datasets. This dissertation analyzes the complex interplay between over 100 variables and provides one of the first research attempts at better understanding the processes that lead to the deep-rooted and comprehensive implementation of sustainability curricula. Internal and external practitioners of higher education institutions can find examples and evidence that can be useful in planning the next steps of their sustainability curriculum implementation. In the future, higher education institutions will play an even greater role in the journey toward sustainable development. This dissertation offers generalizable empirical findings on how universities can succeed in recognizing their own responsibility to that end and in realizing this transformation through the implementation of ESD.

Mental health is an important factor in an individuals’ life - more than 300 million individuals suffered from depression in 2015. Online-based interventions have been developed for the treatment of various mental disorders. These types of interventions have proven their efficacy and can lead to positive outcomes for suffering patients. During these interventions, a large amount of patient-specific data is gathered that can be utilized to increase treatment outcomes by informing decision-making processes of psychotherapists, experts in the field, and patients. The articles included in this dissertation focus on the analysis of such data collected in digital psychological treatments by using machine learning approaches. This dissertation utilizes various machine learning methods such as Bayesian models, regularization techniques, or decision trees to predict different psychological factors, such as mood or self-esteem, dropout of patients, or treatment outcomes and costs. These models are evaluated using a variety of performance metrics, for example, receiver operating characteristics curve, root mean square error, or specialized performance metrics for Bayesian inference. These types of analyses can support decision- making for psychologists and patients, which can, in turn, lead to better recommendations and subsequently to increased outcomes for patients and simultaneously more insight about the interplay between psychological factors. The contribution of this interdisciplinary dissertation is manifold and can be classified at the intersection of Information Systems, health economics, and psychology. The analysis of user journey data has not yet been fully examined in the field of psychological research. A process for this endeavor is developed and a technical implementation is provided for the research community. The application of machine learning in this context is still in its infancy. Thus, another contribution is the exploration and application of machine learning techniques for the revelation of correlations between psychological factors or characteristics and treatment outcomes as well as their prediction. Additionally, economic factors are predicted to develop a process for treatment type recommendations. This approach can be utilized for finding the optimal treatment type for patients on an individual level considering predicted treatment outcomes and costs. By evaluating the predictive accuracy of multiple machine learning techniques based on various performance metrics, the importance of considering heterogeneity among patients’ behavior and affect is highlighted in some articles. Furthermore, the potential of machine learning-based decision support systems in clinical practice has been examined from a psychotherapists’ point of view.

Summary Since the early 2000s, ecosystem services strongly gained significance as a research topic. While the number of papers strongly increased, the concept was further developed which changed the way it was applied. From highlighting the value of ecosystems by viewing them not only from an ecological, but also from an economic perspective in the beginning, it is nowadays, among others, used to map and calculate the monetary value of ecosystem services. Lately, the International Panel on Biodiversity and Ecosystem Services (IPBES) further developed the concept into Nature’s contributions to people (NCP) which puts a stronger emphasis on stakeholders and indigenous knowledge. However, so far none of the conceptual developments managed to integrate the temporal dimension of ecosystem services into this concept, although this should be the basis for a sustainable long-term management of ecosystems and their services. Therefore, I present three articles in this thesis that deal with temporal aspects of ecosystem services. In two of them I also present a proposal for a framework for the classification of ecosystem services based on their temporal dynamics. In this dissertation I differentiate between two types of temporal aspects, both of which have in common that change takes place over a certain period of time. The concepts of transformation, transition and regime shift are used to describe changes in social or ecological systems as a whole, for example the transformation towards a more sustainable society. The temporal dynamics that I present, on the other hand, relate to the temporal changes in ecosystem services themselves. The first article focuses on how the literature on ecosystem services incorporates social and ecological change, illustrated by the concepts of transformation, transition, and regime shift. The second and third articles deal with the temporal dynamics of ecosystem services. While the second article presents a preliminary framework for categorizing the temporal dynamics of ecosystem services, the third article uses this framework to test how the temporal dynamics of ecosystem services are represented in the literature. Based on the insights from the three articles, I conclude that most of the studies on ecosystem services only focus on one point in time. One reason for this is that most studies are conducted over a maximum of a four-year time span which does not allow to monitor dynamics over longer time spans. In most articles that do account for temporal aspects, the focus is strongly on the side of ecological supply of ecosystem services rather than on the demand-side which leads to the exclusion of stakeholder perceptions and therefore, makes it impossible to connect ecosystem service demand and supply over time. Moreover, the concept of change that is used most often in the literature is that of regime shifts which comes from a purely ecological background and focuses mostly on changes that happened in the past. This neglects the possibility of change towards a positive outcome in the future. In general, there is a strong disciplinary divide in the concepts and terminology used. This leads to a lack of exchange between different scientific disciplines and non-academic stakeholders. Approaches that are needed to solve problems of ecosystem service management are therefore impeded. To enable future research to better account for temporal aspects and connect supply and demand sides of ecosystem services with each other, I give four recommendations for future research. These are (I) take temporal dynamics into account by conducting long-term research, (II) ensure conceptual clarity, (III) create a solution-oriented agenda and (IV) take the demand side into account by involving stakeholders’ perceptions over time. By following these recommendations, future research could help to support the sustainable management of ecosystem services as dynamics will be better known and targeted measures can be implemented.

The global food system faces many complex challenges, and there is general agreement that a transformation is needed. While localizing food has been proposed as a means to this end, changing global food supply chains may also lead to sustainable food systems. Because most food systems today have an international dimension and are likely to remain connected, on one way or another, to other ones across the globe, it is necessary to find solutions to problems such as exploitation or environmental degradation. Current approaches such as Fairtrade certification often result, however, only in incremental change, and it is not clear how the current system could be transformed to make it sustainable. Addressing this challenge and the related gap in the literature, this study examines the emerging practices of small intermediary food businesses, which act between agricultural producers and consumers, and may have the potential to advance sustainability in international food supply. Including a systematic review of the literature on food systems change (Study#1), this dissertation adopts a transformational sustainability research methodology, which is solutionoriented, aims to integrate system, target and transformation knowledge, and is characterized by a transdisciplinary research practice. It conceptualizes challenges of international food supply and empirically investigates entrepreneurial solution approaches to address these challenges (Study#2). Two transdisciplinary research projects with small coffee businesses located in Germany, Mexico, and the U.S. were conducted to examine how these approaches could be implemented (Study#3, Study#4, Workshop reports 1+2). This study shows that challenges in international food supply chains can be conceptualized as negative effects of large geographical and relational distances. It also identifies five entrepreneurial solution approaches specified by twelve sustainability-oriented design principles to address these negative effects. Creating relational proximity between supply chain actors, that is, strong relationships based on knowledge and care, seems to be a key factor to advance sustainability in international food supply.The results also suggest that by building such strong relationships and changing the fundamental principles of international food trade (e.g. putting people before profits), small intermediary businesses could be important agents in food system transformations. The findings also highlight the importance of collaboration with peers in local networks, in which new sustainable business practices could be shared and disseminated. Transdisciplinary collaborations involving both researchers and small food businesses could result in innovative solutions and, ultimately, a transformation of food systems. Although the small-sized businesses examined here are already highly committed to sustainability, this study has important implications for researchers and practitioners, including individual entrepreneurs, who aim to advance sustainability in international food supply.

The texts gathered in this manuscript offer a largely congruent set of insights on the cultural dimension of sustainability and on the important functions of the arts in relation to the cultural dimension of sustainability, not only in society – more particularly in cities – but also more self- reflexively in transdisciplinary sustainability research itself. The introduction paper (original text for the Cumulative Habilitation) presents all the published texts included in the cumulative habilitation manuscript, and discusses the challenges of transdisciplinary research, differentiating two schools of transdisciplinarity (the so-called the ‘ETH’ and ‘CIRET’ approaches) to which the author’s postdoctoral research relates. The four texts in the first part (PART 1 - Culture(s) and Aesthetics of sustainability)articulate the relations between culture and sustainability. They focus on a theoretical dimension of the author’s postdoctoral research that further developed an understanding of “cultures of sustainability” and of “aesthetics of complexity” that was initiated in the author’s PhD, bringing them in a dialogue with other ongoing and emerging discourses about “cultural sustainability” and “queer ecologies”. The four texts in the second part (PART 2 - The Arts in Relation to Culture(s) and Aesthetics of Sustainability) represent the part of the author’s research that constituted a closer examination of specific artistic practices: ecological art, musical practices, and contemporary interdisciplinary arts in urban arts organizations. The ten texts in the third part (PART 3 - Creative Sustainable Cities) share the insights gained in the parts of the author’s research work that focused on urban cultural and arts-related phenomena in their relationships to urban sustainability. Several of the texts lay out a critique of the “Creative City” and demonstrate an effort to develop an alternative understanding of the Creative City that would deserve to be also named a “Sustainable City”. Later texts share the insights from the author’s co-leading of the “Stadt als Möglichkeitsraum” (“City as Space of Possibilities”) research project (2015-2018). The nine texts collected in the fourth part (PART 4 - Towards Artful Sustainability Research)reflect how the author’s ongoing research work included a transdisciplinary reflection and development in terms of epistemology and methodology, incorporating increasingly more elements of arts-based research and of phenomenology and integrating them with systems thinking and qualitative social-scientific research. This development brought the author to reflect further upon the imaginaries and research practices of sustainability researchers, and to advocate for an “artistic turn” in sustainability research (including the more specific field of sustainability science). The conclusion paper (original text for the Cumulative Habilitation) summarizes the insights from all the published texts included in the cumulative habilitation manuscript, and suggests ways to address the transdisciplinary challenges presented in the introduction paper, suggesting ways to articulate the ‘ETH’ and ‘CIRET’ approaches to transdisciplinarity.