Differentiated EU integration: maps and modes

Abstract

This paper reports a descriptive analysis of the historical development and the modes of differentiated integration in the treaties and legislation of the European Union. Whereas the number of differentiations has increased in the course of European integration, it has remained stationary relative to the growth of the EU’s membership, policy portfolio and legal production. Differentiated integration is predominantly multi-speed integration, typically originating in enlargement, focusing on internal market policies and affecting the comparatively poor Southern and Eastern new member states. In addition, durable differentiations originating in the deepening of the integration of core state powers have created a multitier structure, but the core is inclusive and open. The crisis period of European integration has reinforced the differentiation of the EU for the time being, but both Brexit and the stagnation of widening and deepening are likely to slow down differentiation.