Research on federalism in Germany successfully identified several drivers of diversity among the federal states (Länder). Nevertheless no coherent analytic framework exists which would provide a systematic approach for the causes of diversity in federal Germany.
This paper proposal introduces such an analytic framework into academic discussion. It builds on lines of thought previous scholars have developed and fills gaps left open in research. As many such lines of thought are using common theories of policy analysis such as the party difference hypothesis, institutional or socio-economic factors, this paper combines and expands these theories. First, it discusses the explanatory value of six theories (party difference hypothesis, power resources theory, socio-
economic theory, path dependence, veto player theory and international hypothesis). Particularly the
contribution investigates the adaptability of this theories to the subnational level in federations and
explores valuable hypotheses emerging from them. The goal is to find factors driving diversity in federations with this theoretical framework. Second, the paper proposal delivers a proof of concept by applying the newly developed theoretical framework to transportation infrastructure policy of the German
Länder.
This proof of concept uses a set of four qualitative case studies in different Länder to generate plausible
Hypotheses. Third, the contribution discusses the results of this proof of concept. Are some patterns
emerging? Do they fit into current research on German federalism? Also the need for further research would be highlighted, especially which new case studies would enrich academia.