Research on differentiated integration (DI) in the European Union has burgeoned in recent years.However, we still know little about citizens' attitudes towards the phenomenon. In this article, we argue that at the level of individual citizens, liberal economic values increase support for DI.Stronger preferences for equality, in contrast, make opposition to the concept more likely. Similarly, concerns about discriminatory differentiation at the member state level lead citizens to oppose DI.We test the theoretical claims by analysing survey data on citizens' attitudes towards a 'multi-speed Europe'. Supporters of DI, indeed, are marked by liberal economic attitudes. In contrast to general EU support, we do not find robust correlations with socio-demographic variables. Moreover, the data reveal striking differences amongst macro-regions: support for DI has become much lower in Southern European states. We attribute this opposition to negative repercussions of the Eurozone crisis.

The literature on the relationship between European Union (EU) integration and regional power has produced two opposing theoretical models. Depending on the model, EU integration leads to either an increase or decrease in regional power. Evidence for both, however, has been largely inconclusive, and mostly derived from qualitative case studies.This paper, on the other hand, offers a quantitative, large-N analysis, using data from fiftysix countries between 1960 and 2010. Its random effects model shows that EU membership considerably increases regional authority within member states over time; and its comparison with another international organization suggests that the effect is not idiosyncratic.Additionally, this paper finds support for two possible mechanisms: the establishment of the subsidiarity principle, and the Commission's requirement to create regional government structures.