Bicameral politics in the European Union

Quantitative research in the field of European Union (EU) politics has focused on the internal dynamics of either the Council of Ministers (the Council) or the European Parliament (the Parliament). Theoretical accounts of bicameralism in the EU have understood the Parliament as a unitary actor. As a result, little attention has been paid to the effect of different majority requirements in the Parliament on its institutional powers vis-à-vis the Council. This paper contributes to the empirical knowledge in the field by investigating bicameral political dynamics based on a combined data set covering legislators’ behavior in both the Council and the Parliament. Theoretically, the analysis supplements the standard understanding of the formal relationship between the EU institutions. It shows that the Council has the upper hand in bicameral negotiations as it is harder for the Parliament to amend or reject the common position of the Council than it is to accept it. When disagreement is recorded in the Council, the institutional imbalance increases as the polarization along the left-right axis in the Parliament is strengthened. This challenges the unity of the Parliament against the Council’s common position, making it less likely that the center-left and center-right can form sufficiently large coalitions for effectively defending the Parliament’s position vis-à-vis the Council.