The Impact of Differentiation on EU Governance: Effectiveness, Sustainability and Accountability

This research paper aims to offer an innovative and comprehensive assessment of the impact of differentiation on EU governance. It addresses the organizational, constitutional and socio-political factors affecting differentiation and integration in the EU in order to assess the effectiveness, sustainability, accountability and legitimacy of differentiated arrangements within the EU and between the EU and participating third countries. The ultimate aim is to provide an overall appraisal of how much and what form of differentiation propels European integration forward – as a whole and for specific policy areas – and what kinds of differentiation should be avoided to prevent disintegration in the future. The empirical research shows that formal arrangements of differentiation are not only compatible with, but also conducive to a more effective, cohesive and democratic Union when they have a direct link to EU institutions, are established with clear objectives in line with EU core values, and are equipped with adequate mechanisms to ensure accountability and to connect ins and outs. On the contrary, excessive flexibility entailed in looser forms of differentiated cooperation that are established outside the EU Treaties are likely to produce fragmentation dynamics and ultimately jeopardise the EU’s political unity and normative consistency.