Income Inequality and Political Polarization: The View from Within Congress

As economic inequality has increased in the U.S. over the past three decades, measures of political polarization between the two parties based on roll call votes in Congress have risen. Yet, it remains to be seen whether the legislative behavior of representatives in Congress is tied to the economic circumstances of their constituents, and whether increasing economic disparities between congressional districts can be linked to rising political polarization.

Political scientists David Epstein, James Fowler, and Sharyn O’Halloran will address these questions by studying the relationship between the median income of congressional districts and patterns of roll call voting as well as the co-sponsorship of bills between 1978 and 2006. Having first calculated the median income for all congressional districts, the research team will analyze congressional representatives’ votes on policies aimed at reducing inequality. In addition to voting behavior, the investigators will examine co-sponsorship of over 10,000 bills in the House of Representatives. Epstein and colleagues will then analyze the 14,000 bills that passed a floor vote in order to determine which co-sponsorships were actually effective in helping the poor. This information will allow the research team to extrapolate the extent to which representatives from poor neighborhoods participate in effective coalitions or remain marginal and ineffective. The results of the project will be presented at several national political science conferences and formally reported in a Russell Sage volume.