Different Efforts in E uropean Economic Integration: Implications of the EU I ndex

E uropean integration is a multilayer process consisting of significant differences in efforts and capabilities of the M ember S tate's individual EU participation. Hence, general statements about the national level of E uropean economic integration are very vague. In order to fill this gap, this article presents a composite indicator measuring the extent of economic integration within the E uropean U nion – the EU I ndex. Existing composite indicators concerned with economic integration (globalization indices) were not designed to capture the specific E uropean dimensions. The EU I ndex offers a unique basis, as now the national differences can be illustrated by one statistical measure. Large heterogeneities are found between the M ember S tates with respect to overall E uropean economic integration and to various sub‐indices. By using cluster analysis, it is also shown that the prevailing economic heterogeneities in the EU are combined with a strong and even growing clustering of its members, thereby challenging present and future steps of E uropean integration.