Investing in Agreement: Party Organization, Leadership Change, and Policy Positions


Party unity is a key feature of the political landscape. The degree of observed unity is an important element of the clarity and strength of party positions, but the critical question of how the preferences of party leaders and backbenchers feed into a common position is largely unasked. We argue that intraparty organization is critical both for party positioning and for the volatility of those positions. Whether and when backbenchers who would like to change their party’s position can gain the influence to put their desires into practice depends on how and to whom intraparty structure and process provide opportunities for influence. In this paper, we model the incentives for rank-and-file party members who might like to change their party’s position to nonetheless support leadership decisions. Contrary to the expectations generated by veto player theory, our signaling game suggests that changes in the policy content of party labels should be more frequent in political parties with complex leadership structures (i.e., more party members with influence in party decision making). We test our model empirically utilizing party-position data drawn from election manifestos.