Police Officer Assignment and Neighborhood Crime

We develop an empirical model of the mechanism used to assign police officers to Chicago districts and examine the efficiency and equity of alternative allocations. Chicago, like most major US cities, uses a bidding process that grants priority based on seniority, resulting in the assignment of the least experienced officers to the most violent and lowest-income neighborhoods. Our empirical model combines estimates of heterogeneous officer preferences underlying the bidding process with causal estimates of officer experience on neighborhood crime and policing. We find that more experienced officers are more effective at deterring violent crime while also being much less likely to use force in comparable policing contexts. We estimate that equalizing officer seniority across districts would reduce Chicago’s overall violent crime rate by 4.6 percent and officer use of force by 10 percent. Inequality in crime, and officer use of force across neighborhoods would also decrease sharply. Given officer preferences, we show that this assignment can be achieved in a revenue-neutral way while resulting in small welfare gains for police officers, implying that it is both more equitable and more efficient.