Modeling Interest-Group Campaign Contributions

Abstract

This article models the allocation of contributions by a Political Action Committee (PAC) among a group of candidates running in different races, assuming utility maximizing behavior on the part of the PAC and the candidates. Under various assumptions about objectives, contributions are found to flow toward races that are expected to be close. No model examined yields a clear prediction that contributions flow to likely winners, but it is argued that a skewing of contributions toward incumbents might indicate that contributions are being exchanged for current political favors. Some empirical analysis of contributions by nine large PACs to candidates for the 1978 U.S. House of Representatives is carried out. For the most part, both closeness of race and incumbency appear to increase the likelihood that a candidate will receive contributions.