Over the past 60 years, European countries dealt with problems of regional governance in very different ways. The common theme to this diversity is the debate between supporters of local government mergers and those favouring local government autonomy and self-determination to protect democracy and responsiveness to citizens. The significant amount of scholarly contributions to this lively debate between amalgamation and fragmentation contrasts with the scarcity of theoretical attention and empirical assessment of decentralized self-organizing mechanisms for regional governance. This paper describes the Institutional Collective Action (ICA) framework and its application to the study of collaborative mechanisms in metropolitan areas in the European context. We discuss a set of theoretical propositions to explain the variation in the adoption of collaborative mechanisms by Northern vs. Southern as well as Eastern vs. Western European countries. The paper concludes by advancing a research agenda for the study of decentralized regional governance in Europe.
