The European Union pursues what are called common policies in the key areas where it is competent to make binding supranational laws. Questions over the distribution of national power and the member states' degree of control over decisions are crucial factors behind the direction of EU policies. They are usually analysed by the control measures of cooperative games. But, in general, voting weight is a poor proxy for measuring power. The distribution of power in the EU has been analysed in earlier studies by using the traditional voting power measures of game theory, namely the Shapley-Shubik and Banzhaf indices. As regards the national policy impact, the basic weakness of the traditional measures is that they examine the policy influence via the voting outcomes.

In Discussion Paper No. 1033, Research Affiliate Mika Widgrén argues that there can be significant differences between a country's voting power and policy impact. He uses Holler's analysis to derive an exact formula which decomposes the traditional voting power measure into what he calls luck &nbspand decisiveness components. Outcomes involving free-riders are disregarded. The paper also investigates how member states' cooperation affects a single country's policy impact. The results reveal that the small countries have more influence on EU policies than they have on voting in the EU Council. The large countries, in contrast, are more powerful in voting than in policy content.

The Relation Between Voting Power and Policy Impact in the European Union
Mika Widgrén

Discussion Paper No. 1033, June 1994 (IT)