The Impact of the Accession of the Western Balkan Countries on Voting and Coalition Formation within the European Council of Ministers

This paper looks into the impact the accession of the Western Balkan countries of Albania, Serbia, Montenegro, Croatia, Bosnia and Herzegovina, and FYROM would have on voting power in the EU Council. Particular attention is paid to the implications of a priori coalitions between member states. The Shapley-Shubik power index is used to estimate voting power and two scenarios are considered: accession under the Nice Treaty and the Reform Treaty rules. If the Western Balkans accede under the Nice Treaty rules then the efficiency and workability of the EU would deteriorate, although the “paradox of new members” might occur where the power of some existing members is increased. Conversely if the accession took place under the Reform Treaty rules then there would be little impact on the ability of the EU to act. The inefficiency of a priori coalition formation between countries of dissimilar size is revealed, as well as the likely occurrence of the “paradox of size” where some countries are made worse off through cooperation. The enlargement will not affect this.