Do policy attributes matter? A policy-centred approach to European integration

The differentiation of European integration recently gained renewed attention from European integration scholars. Despite countless studies on the European integration process, most scholars have neglected policy attributes as an explanation for the variance of the integration depth across countries. In this article, we adopt a policy-centred perspective to analyze the differentiation of European integration across policies and countries. By combining different data sources, we construct an original data set and study the European integration process in the EU-15 from 1989-2011. The empirical analysis shows that the European integration process chiefly hinges on policy attributes: The higher the public support to integrate a policy area at the European level, the higher the integration level of this very policy. In addition, policy fields in which decision making at the EU level leans to the right are more integrated then when decision making tends to the left. By contrast, member state characteristics only have a minor influence on integration depth. These findings suggest that we can no longer neglect differences across policy areas when studying the European integration process.