Political ambition and legislative behavior in the European parliament

Members of the European Parliament (MEPs) typically follow one of two career paths, either advancing within the European Parliament itself or returning to higher offices in their home states. We argue that these different ambitions condition legislative behavior. Specifically, MEPs seeking domestic careers defect from group leadership votes more frequently and oppose legislation that expands the purview of supranational institutions. We show how individual, domestic-party, and national-level variables shape the careers available to MEPs and, in turn, their voting choices. To test the argument, we analyze MEPs roll-call voting behavior in the 5th session of the EP (19992004) using a random effects model that captures idiosyncrasies in voting behavior across both individual MEPs and specific roll-call votes.