Some recent work on interest groups has studied how the evolution of political institutions, notably the emergence of multi-level governance, has transformed the organization of interests in European countries (e.g. Keating and Wilson 2014). Whereas much of this work has considered the implication of this evolution for interest group strategies and multi-level venue shopping (e.g. Beyers and Kerremans 2012), the repercussions for the organizational development of national interest group communities have received less attention. For instance, little is known on how this European experience with multi-level governance – the shifting of policy functions to multiple levels of governance – affects organizational centralization or the persistence and viability of local chapters (but see work on the US experience, for instance Skocpol 2003; Miller 2008). In this paper, we demonstrate that the prevalence of multilevel governance fosters a diverse organizational landscape with a mix of highly centralized groups and groups that strongly depend on local chapters. For this purpose we rely on a unique dataset that maps patterns of centralization and decentralization for all national interest groups in Belgium, an EU member state that can be characterized as an extreme example of multilevel governance.
