Аннотация:How does the ideological profile of a political party affect its support or opposition to European integration? The authors investigate this question with a new expert data set on party positioning on European integration covering 171 political parties in 23 countries. The authors’ findings are (a) that basic structures of party competition in the East and West are fundamentally and explicably different and (b) that although the positions that parties in the East and West take on European integration are substantively different, they share a single underlying causality.
