Do the rich speak louder? : examining whether U.S. Senators differentially respond to their constituents by income across issues

Abstract

This thesis examines the relationship between public opinion and the way senators vote on specific issues, and how this "responsiveness" might vary across income groups. The independent variable of interest, state-level income group preference, is estimated using multilevel regression and post-stratification (MRP) analysis. This is an improvement over earlier methods, particularly when modeling income group level opinion where there are insufficient sample sizes in national surveys. Income group opinions are found to be distinct across issue areas and the top ten percent of the income bracket are found to hold different opinions when compared to a more inclusively defined high-income group. Ideal point estimation is used to generate the dependent variable of senator responsiveness based on roll call votes. The first-stage MRP estimates of state-level income group opinion are then regressed on the corresponding senators' ideal points by issue area. While this paper expected the second stage analysis to support an Instructed-delegate model of responsiveness, where senators vote in accordance with constituents' interests, no evidence of such a relationship is found, even at the aggregate opinion level. The evidence suggests that senators are looking elsewhere when making their policy decisions.