Identifying and Measuring Excessive and Discriminatory Policing

Abstract

We describe and apply three empirical approaches to identify superflu-ous police activity, unjustified racially disparate impacts, and limits to regu-latory interventions. First, using cost-benefit analysis, we show that traffic and pedestrian stops in Nashville and New York City disproportionately im-pacted communities of color without achieving their stated public-safety goals. Second, we address a long-standing problem in discrimination re-search by presenting an empirical approach for identifying “similarly situat-ed” individuals and, in so doing, quantify potentially unjustified disparities in stop policies in New York City and Chicago. Finally, taking a holistic view of police contact in Chicago and Philadelphia, we show that settlement agreements curbed pedestrian stops but that a concomitant rise in traffic stops maintained aggregate racial disparities, illustrating the challenges fac-ing regulatory efforts. These case studies highlight the promise and value of viewing legal principles and policy goals through the lens of modern data analysis—both in police reform and in reform efforts more broadly.

Keywords: Policing, discrimination, disparate treatment, disparate impact