Conference Contribution Details
Mandatory Fields
Costello, R
Midwest Political Science Association Annual Conference
Does Bicameralism Promote Stability? The impact of bicameral agreements on coalition formation in the European Parliament
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The institutional arrangement of bicameralism has often been defended as a solution to the problem of legislative instability. It is claimed that equilibrium outcomes are more likely to exist under bicameralism, thereby making decision making more stable and predictable.  The complex legislative system of the European Union, which is occasionally bicameral, provides a unique opportunity to empirically test this claim. The ‘codecision’ procedure involves intensive negotiation between the two legislative chambers, the European Parliament and the Council of Ministers; final decisions made under this procedure must have the support of concurrent majorities in both chambers. In contrast, decisions reached in the Parliament under other procedures are not necessarily supported by the Council.  In line with expectations, the results show that coalition formation in the European Parliament is more stable and predictable when bicameral agreements are required. In particular, the median party on the left-right dimension is pivotal to agreements under codecision.