The question of the distribution of legislative power among the main EU institutions and its variation within the main legislative procedures has long been at the heart of EU scholarship. There is agreement on the major developments, however, all models and measurements have been contested. This paper develops a new approach to modeling EU decision-making based on extensive form games reflecting possible decision paths for each legislative procedure. Data from the PreLex database (Haege 2011) is used to evaluate the distribution of legislative power among the Council of Ministers, the European Parliament and the European Commission. We find that only a small fraction of all possible decision paths are actually used and that only around 6% of all proposals fail. The Parliament has clearly gained power through Cooperation, and more so, through Co-decision. In Co-decision II the Commission proposal is immediately accepted in 13 % of all cases, the Parliament successfully amends almost 40% of proposals during the First Reading. In the remaining cases Council and Parliament are on equal footing in the Second Reading, each pushing through its preferred alternative in about 18%, and finding a compromise in 11% of all proposals.
