Ideology and Interests in the Political Marketplace

I develop a statistical method to measure the ideology of candidates and political action committees (PACs) using contribution data. The method recovers ideal points for incumbents that strongly correlate with ideological measures recovered from voting records, while simultaneously recovering positions for PACs, unsuccessful challengers, and open‐seat candidates. As the candidate ideal points are estimated independently of voting records, they represent a useful new resource for testing models of legislative behavior. By incorporating nonideological covariates known to influence PAC contributions, the method also shows promise as a platform for furthering our understanding of PAC contribution behavior.