No Runs, Few Hits, and Many Errors: Reasonable Suspicion and Bias in Street Policing in New York

• In Event: Proactive Policing in New York: Social and Legal Impacts of Two Decades of Stop and Frisk

Abstract

We use a “hit rate” model of racial discrimination to test for evidence of bias in the conduct of police stops in New York’s Stop, Question and Frisk regime. Hit rate tests suggest that without racial discrimination, the proportion of searches detecting crime (or “hit rate”) will be equated across races. Maintaining a racial or ethnic imbalance of police stops in the face of low “hit” rates suggests a taste for discrimination. An unbiased officer would maximize her hit rate by reducing the number of unproductive stops toward the group with the lowest hit rate, suggesting tastes for justice and safety. We exploit data on 4.4 million stops over 10 years to test for bias both in the selection of persons for stops and in the application of 4th Amendment criteria regulating these stops. We find that (1) Blacks and Black Hispanics are less likely to be sanctioned and produce guns or drugs; (2) if sanctioned, Blacks and Black Hispanics more likely to be arrested compared to less intrusive actions; and (3) the bases of suspicion that animate stops are racially imbalanced in the face of lower “hit rates.” Implications for internal and external regulation of police stops are discussed.

Authors

• Jeffrey Fagan, Columbia Law School

• Gregrory Conyers, Yale University

• Ian Ayres, Yale University