Much attention is being paid to the planning of public-private partnership (PPP) infrastructure projects. The subsequent implementation phase – when the contract has been signed and the project ‘starts rolling’ – has received less attention. However, sound agreements and good intentions in project planning can easily fail in project implementation. Implementing PPP infrastructure projects is complex, but what does this complexity entail? How are projects managed, and how do public and private partners cooperate in implementation? What are effective management strategies to achieve satisfactory outcomes? This is the fi rst set of questions addressed in this thesis. Importantly, the complexity of PPP infrastructure development imposes requirements on the evaluation methods that can be applied for studying these questions. Evaluation methods that ignore complexity do not create a realistic understanding of PPP implementation processes, with the consequence that evaluations tell us little about what works and what does not, in which contexts, and why. This hampers learning from evaluations. What are the requirements for a complexity-informed evaluation method? And how does qualitative comparative analysis (QCA) meet these requirements? This is the second set of questions addressed in this thesis.
The main research objective of my thesis is to contribute to a broader understanding of social inequality by going beyond inequalities solely derived from the labor market and find theoretical arguments as well as empirical evidence for the establishment of wealth as a distinct dimension of social stratification and, more importantly, of social inequality. With social stratification, I am referring to a society’s ranking of categories of individuals into a hierarchy of social positions. Social stratification becomes social inequality if access to these positions is unequal and if these positions are systematically related to advantageous or disadvantageous conditions of acting and living. In the course of my thesis, I will show that both these conditions apply to wealth: first, access is unequal and second, being of higher (lower) wealth is related to advantageous (disadvantageous) conditions of living. My thesis consists of five empirical studies that are knotted together by the common conception of wealth as a distinct dimension of social inequality. In order to find empirical support for this argument, in each study, I will approach the topic of wealth, or wealth inequality, from different perspectives. All studies represent theory-driven empirical analysis and are designed as international comparative studies.
In this PhD thesis the question “What makes firms innovative?” is evaluated. In particular, the thesis investigates the differential impact of inter-organizational social networks comprising various different corporate partners on the knowledge stock of a company, evaluates how and to what extent internal knowledge capabilities contribute to innovation success, and scrutinizes how both inter-organizational social networks and internal knowledge capabilities interact and thereby affect innovation success. Therefore, the thesis combines the social capital theory and the concept of absorptive capacity on an organizational level and applies survey data from the German manufacturing industry. Among others, the thesis shows that, first, innovativeness of external partners is contagious, second, that besides customers especially R&D partners can be valuable sources of different types of knowledge, and, third, how the usage of knowledge management systems fosters innovation success. Thereby the results contribute not only to the innovation literature and, in particular, to the open innovation literature, but also to the research fields of inter-organizational knowledge transfer, absorptive capacity, and social capital theory.