The extent to which an executive body is able to set the legislative agenda relative to other legislative actors is a crucial component of the inter-institutional balance of power in all polities. This is also the case in the European Union, where the European Commission is commonly seen as the predominant agenda-setter due to its right to initiate legislative proposals. While Commission agenda-setting power is acknowledged in the literature, measuring the impact of this right on legislative outcomes has to date proven difficult due to the lack of suitable data. This paper addresses this gap in the literature by considering the changes between the Commission's proposals and the final legislative outcome passed by the Council of Ministers for all legislative proposals between 1999 and 2012. It does so by implementing an article-by-article Levenshtein distance algorithm to measure changes between legislative proposals and outcomes. The extent of these changes is inversely related to the power of the Commission to get the Council and Parliament to agree to the policy positions in its proposal and varies across institutional settings. This new measure of agenda-setting power, when combined with information about actor preferences and the institutional environment, allowing us to empirically evaluate prominent theories of inter-institutional agenda-setting in the EU. The findings presented suggest that the ability of the Commission to set the agenda is determined by the institutional structure in which negotiations take place, and the constellation of actor preferences over the legislation under negotiation. Our conclusions contribute to the ongoing debate on the nature and distribution of executive functions in the European Union.
