You can download the data that we have used in our JCMS publication here: EU-Index.xlsx
You can find the data of the EU-25-Index (updated to 2012) here: EU-25 Index
Indicators used in the EU-Index:
Single Market
EU openness
EU importance
EU Homogeneity
EU Symmetry
Institutional Conformity
EU participation
EU compliance
Note: “intra-European”, “European” and “EU average” refer to the respective EU-14.