Labor PAC contributions and labor legislation: A simultaneous logit approach

Labor PACs are used to explore the potential congressional influence of campaign contributions from special interest groups. PACs of organized labor are particularly useful for two reasons. First, a set of labor issues are defined each year by the AFL-CIO and so ad-hoc decisions about pertinent legislation are not made by the researcher. Secondly, there are measurable traits of representatives and constitutents that may lead to a predisposition of labor support. By combining these two attributes, a model is developed to investigate the question of congressional influence. A wider set of PAC strategies is allowed to operate in this formulation than previous studies. A series of roll-call votes is used to construct an index reflecting the probability that a representative will vote in favor of labor legislation. Therefore, labor PACs may contribute money to various members of congress hoping to sway their vote on a specific issue, a variety of issues, or they may simply want to increase their chances of obtaining access when issues of interest arise. The latter access-oriented strategy may affect the general trend in legislation even though its influence on specific bills is uncertain a priori. Because the dependent variable is a fraction based on samples from binomial populations, a quantal choice model is required. The simultaneous-logit formulation used here allows for the joint determination of PAC dollars and voting probabilities while exploring this discreet choice. The results of this study provide evidence that labor PACs are able to affect legislation. In both congressional terms studies, the tendency of a representative to support labor issues was directly related to the size of campaign contributions from labor PACs. Furthermore, these results suggest that the interaction between funds and legislation ran in both directions, i.e., additional labor funds increased pro-labor votes and at the same time representatives with a predisposition to vote for labor also receive more funds from labor PACs. Further hypothesized relationships were also tested. Representatives are more likely to support labor legislation when their constituents are unionized and less likely when constituents are conservative. Members of the Democratic Party lean towards labor, while congressmen and congress-women from states with right-to-work laws tend to oppose labor issues. With all of these characteristics included in the regression model, PAC money is still important. The determinants of labor PAC contributions include ideological measures, the Representative's of political clout, and measures of the need for funds in addition to the simultaneous interaction with labor voting probabilities. Democrats and members of House committees of importance to labor received greater funds while incumbents facing a strong challenger also increased their PAC receipts. These results are consistent with previous works. Labor PACs appear to have the ability to influence legislation through the manipulation of campaign contributions. Whether PACs are able to directly purchase a particular vote probably depends on the issue i.e., some studies have founds evidence of vote-buying while others have not. But if a broader spectrum of PAC concerns are considered, the evidence appears to be more convincing. PACs seem to have an impact. Copyright Martinus Nijhoff Publishers 1987