The Constitutional Choice of Rules. An Application of the Absolute and Relative Power Concepts to European Legislation

European legislation is an often studied topic of research into decision rules, since it provides for a large number of different rules and the interaction of different voting bodies. However, research on European Integration concentrates on the choice rather within than of rules. Relative voting power analyses stress the distributional consequences of different voting weights within the Council of Ministers, while spatial models emphasize the inter-institutional interaction among the Commission, the Council of Ministers and - sometimes - the European Parliament. They both fail to give a satisfactory account for the constitutional choice of different procedural settings. Whereas relative voting power analysis disregards the important distinction between strong and weak decision rules, spatial models are not able to explain the un-equalness of rules. In this paper, we clarify the differences between both approaches by providing an analytical tool to measure absolute and relative power. We introduce our inclusiveness concept which outlines the notion of absolute power. Moreover, we argue that the combination of both aspects, absolute and relative power, gives an insight into the choice of rules. To generalize our findings we present the concept of entities and inter-institutional sets of winning coalitions which are the cornerstones of the game-theoretical measurement of absolute and relative power in political systems. We then present two appropriate indices measuring both aspects of power. Finally we apply both indices to the variety of European legislative settings with regard to different policy domains