Party Polarization and Electoral Accountability

In this paper we model the interaction between parties and candidates to highlight the mechanisms by which parties selecting candidates may discipline legislators. Parties are long-lived institutions providing incentives to short-lived candidates. Citizens have preferences over a multimentional policy space comprising an ideological and a monetary dimension. Candidates are policy motivated on the ideological dimension only and have opposing interest with respect to citizens on the monetary dimension. Policy motivation implies that candidates care more about winning elections the bigger the ideological distance from the candidate of the opponent party. Therefore, parties can use strategically polarization to provide incentives to candidates. Because of this strategic use, the polarization of the political race may diverge from the polarization of voters' preferences. In general, the polarization of the political race is a compromise between policy preferences of party members and electoral goals. Finally, when parties converge to the median voter, electoral accountability is inevitably compromised