Designing the Voting System for the Council of the European Union

This paper examines thesystem of Qualified Majority Voting, usedby the Council of the European Union, fromthe perspective of enlargement of theUnion. It uses an approach based on powerindices due to Penrose (1946), Banzhaf (1965) and Coleman(1971) to make two analyses: (1) the question ofthe voting power of member countries fromthe point of view of fairness, and (2) thequestion of how the threshold number ofvotes required for QMV should bedetermined. It studies two scenarios forchange from 2005 onwards envisaged by theNice Treaty: (1) no enlargement, the EUcomprising 15 member countries, and (2)full enlargement to 27 members by theaccession of all the present twelvecandidates. The proposal is made that fairweights be determined algorithmically as atechnical or routine matter as themembership changes. The analysis of how thethreshold affects power shows thetrade-offs that countries face betweentheir blocking power and the power of theCouncil to act. The main findings are: (1)that the weights laid down in the NiceTreaty are close to being fair, the onlysignificant discrepancies being theunder-representation of Germany andRomania, and the over-representation ofSpain and Poland; (2) the thresholdrequired for a decision is set too high forthe Council to be an effective decisionmaking body.