Trans-Institutional Cooperation in EU Legislative Politics

This paper sheds light on trans-institutional cooperation of actors across institutional divides. Under the ordinary legislative procedure, it is easier for Member States in the Council to adopt the amendments the Commission supports (Art.293, 294(9) TFEU). This incentivizes trans-institutional cooperation of actors in the Council of Ministers and the European Commission. In a similar vein, this holds for actors in the EP. Commission responsiveness to the preferences of actors in the two chambers helps explain legislative success. Drawing on rational choice institutionalism and a transaction costs framework, the paper presents a model of EU decision-making accommodating the key roles of the institutions' agents, the Commissioner in charge, the EP rapporteur and the Council Presidency, while controlling for their preferences vis-à-vis their respective principal. Hypotheses on preference- and institution-based determinants of legislative cooperation are tested with a dataset comprising information on EP5 and EP6 (1999-2009). The empirical analysis by means of an event-history analysis estimating stratified Cox models provides evidence of cooperation along the lines of the hypotheses developed. The preference alignment and the resulting trans-institutional cooperation of the 'relais actors' transforms the legislative process and helps explain decision-making duration and early agreement. The paper sets these findings into context by discussing the implications for the role of institutions' agents in bicameral politics beyond the EU and highlights avenues for further research.