United in Diversity? European Regulation between Uniformity, Experimentalism, and Differentiation

A key challenge facing the European Union concerns the tension between functional pressures for uniform rules and standards in integrated markets on the one hand and diversity across member states in policy preferences, institutional structures, and socio-economic conditions on the other. This tension has given rise to growing calls for differentiated forms of integration, in which some member states push ahead while others opt out. The underlying assumption is that deeper integration of markets and societies requires uniform rules, which some member states may be politically unwilling or unable to accept, at least initially. Yet a growing body of research has shown that in many core policy domains, EU governance is characterized not by top-down imposition of rigid, uniform regulation, but rather by an experimentalist architecture of framework rulemaking and revision, based on learning from comparative review of implementation experience in different local contexts. Drawing on research conducted within a Horizon 2020 project on “Integrating Diversity within the EU (InDivEU)”, this paper will examine how far and under what conditions experimentalist governance may be an effective and legitimate means of responding to diversity among EU member states, in comparison both to conventional uniform regulation and to differentiated integration. The argument will be developed through a comparative analysis of the evolution of EU regulatory governance in three major policy domains: electricity, banking, and agricultural biotechnology (genetically modified organisms). Based on new empirical research on the institutional design and practical implementation of EU regulatory governance in these domains, the paper will assess the incidence of experimentalist practices, their relationship to formal organizational arrangements, and the extent to which they represent alternatives or complements to differentiated integration.