Neighborhood – MacDonald et al. (2016)

Study Reference:

MacDonald, J., Klick, J., & Grunwald, B. (2016). The effect of privately provided police services on crime: Evidence from a geographic regression discontinuity design. Journal of the Royal Statistical Society (Series A), 179, 831-46.

Location in the Matrix; Methodological Rigor; Outcome:

Neighborhood; General; Proactive; Rigorous; Effective

What police practice or strategy was examined?

The study examines the impact of extra policing conducted by private police on crime. The University of Pennsylvania Police Department (UPPD) deploys officers to the Penn patrol zone in the University City district of Philadelphia, supplementing the police services that the Philadelphia Police Department provides. At any given time, at least 16 UPPD police officers are on patrol within the Penn patrol zone. The study investigates the impact of increased police deployment afforded by UPPD on crime between 2005 and 2010.

How was the intervention evaluated?

Using a regression discontinuity design, the authors compared crime on blocks within the UPPD’s jurisdiction with crime on blocks immediately outside of the UPPD’s jurisdiction that are similar regarding their crime levels and social features.

What were the key findings?

The study estimates that the extra police decreased crime in UPPD city blocks by 43-73% across several crime categories.

What were the implications for law enforcement?

The authors suggest that there are social welfare benefits to hiring extra police for private entities. More generally, the study demonstrates the effects of increasing police presence in urban neighborhoods.

Where can I find more information about this intervention, similar types of intervention, or related studies?