Paper Titles & Abstracts

In this paper, we propose to conceptualize the EU as a system of differentiated integration, in which both the centralization of authority and its territorial scope vary strongly across policies. We argue and show descriptively that vertical and horizontal differentiation is not just a transitional phenomenon but a constitutive feature of European integration, which has become more pronounced over time. Integration theories have focused on the growth in integration but not sufficiently reflected its increasingly differentiated character. We therefore make a theoretical argument to explain why European integration is (increasingly) differentiated and how differentiation varies across policies and countries. We suggest that differentiated integration results from the interaction of (endogenous) interdependence, on the one hand, and politicization, on the other. As both interdependence and politicization vary across policies and countries, they produce vertical and horizontal differentiation.