The Treaty of Nice and qualified majority voting

We analyse and evaluate three decision rules for the Council of Ministers of the EU, which are prescribed by the 'definitive form' of the Treaty of Nice. The first will apply from 2005 to the present 15-member EU, if it will not have been enlarged by then. The second or third will apply to an enlarged 27-member EU. We conclude that the first of these is an improvement on the current decision rule; but the other two have extremely undesirable features.