Differentiated integration in the European Union: Institutional effects, public opinion, and alternative flexibility arrangements

Research on differentiated integration (DI) in the European Union (EU) has focused causes, conditions, and patterns of differentiation integration. By contrast, we know less about its effects institutional outcomes public support; moreover, alternatives to de jure DI providing flexibility are still rarely accounted for. This introduction special issue takes stock of, discusses omissions, current literature DI. We propose an analytical framework, centering efficiency legitimacy, study different types use this framework motivate choice assess contributions articles selected for issue.