The policy impact of leadership in committees: Rapporteurs' influence on the European parliament's opinions

What impact do leaders in the European Parliament's (EP) committees have on the EP's opinions? This study formulates and tests expectations about the conditions under which rapporteurs influence the EP's opinions and also about what factors motivate that influence. In line with the informational theory of legislative committees, the most important factor affecting the EP's opinion is the policy position of the median MEP, not a characteristic of the rapporteur. Nonetheless, the evidence shows that rapporteurs influence the EP's opinions when legislative proposals are subject to early agreements under the co-decision procedure and when the consultation procedure applies. Rapporteurs' influence is motivated primarily by national interests, rather than by the interests of their EP party groups.