On the European level, a variety of different coordination mechanisms are used in different areas of economic policy. The spectrum ranges from complete centralization as in the case of monetary policy to weak forms of coordination like the so-called open coordination in social policy fields. The...

Should a subset of member states of a federation be allowed to form a sub-union on some policy issue? When centralization is not politically feasible, allowing an enhanced cooperation agreement among a subset of countries permits the latter to gain benefits which would otherwise be lost....