Explaining Variation in State Incarceration Rates: The Roles of Poverty and State Ideology

Author: Jessica Nierman

Field of Study: Political Science; Economics

Program Affiliation: Source Project Research Program

Faculty Mentors: Wendy Martinek

Easel: 105

Timeslot: Midday

Abstract: This paper examines why incarceration rates vary across U.S. States. Existing scholarship explains these differences primarily through variations in criminal justice policies, as well as broader social and political characteristics. Building on this literature, the paper argues that differences in state-level poverty rates and citizen ideology are key drivers of incarceration disparities. Specifically, states with higher poverty levels and more conservative ideological orientations are expected to have higher incarceration rates. To test this argument, the study uses state-level data on household poverty rates, based on the federal poverty threshold, alongside measures of citizen ideology derived from survey data and observed political behavior. The results are presented through bar graphs illustrating relationships between incarceration rates, poverty, and ideological orientation. These findings are important because incarceration has far-reaching effects on individuals, families, and communities, and identifying its driving factors can inform more effective policies aimed at reducing prison populations.