ABSTRACT
The traditional decision procedure in the European Union (EU) Council has been a weighted voting system. In the square root system, the voting weight for each state is proportional to the square root of the population. The first voting reform for the Council was initiated at the European Summit in Nice 2000. In Nice the leading European politicians designed a very complicated voting system which was advertised as a compromise between very different demands. The voting system set up by the European Convention has two big advantages over the previous systems; it is relatively simple and it is easy to implement. A fair voting system should not rely on 'smoky backroom' negotiations of voting weights. In many cases we are mainly interested in the relative power of the voters which is given by the Banzhaf Index of voter, which is the Penrose-Banzhaf Measure of voter divided by the sum of the Penrose-Banzhaf Measures of all voters.
