Micro Places – Weisburd & Green (1995)

Study Reference:

Weisburd, D. & Green L. (1995). Policing drug hot spots: The Jersey City Drug Market Analysis Experiment. Justice Quarterly, 12(4), 711-735.

Location in the Matrix; Methodological Rigor; Outcome:

Micro places; Focused; Highly Proactive; Very Rigorous; Effective

What police practice or strategy was examined?

This study tests the impact of an innovative drug law enforcement strategy, developed as part of the Drug Market Analysis (DMA) Program, on drug crime and disorder in Jersey City, NJ. Modeled after preceding hot spots experiences, the department decided that assignment of specific drug hot spots to specific officers would increase accountability for solving drug problems. Officers would engage business owners and citizens in crime control efforts, apply pressure to reduce drug and drug-related activity through police crackdowns, and initiate a maintenance program with the assistance of the police department’s patrol division. In line with tactics employed by street-level narcotics units in other U.S. cities, the control strategy in Jersey City involved unsystematic arrest-oriented narcotics enforcement based on ad hoc target selection. Finally, because many experimental programs fail when gains in crime control are not maintained, it was decided to include an explicit maintenance stage in the program.

How was the intervention evaluated?

The intervention was evaluated using a randomized controlled experiment. Using computer mapping techniques, the researchers identified 56 hot spots of drug activity that were randomized using statistical blocking to experimental and control conditions.The researchers then compared emergency calls for service in the 7-month pre and post intervention periods between areas receiving the intervention and areas which did not.

What were the key findings?

The intervention did not significantly reduce calls for violent or property offenses. However, the intervention did significantly reduce three of four categories of calls for service related to disorder.  Specifically, disorder calls in the control group increased by more than 700 but increased by only 256 in the experimental group (p<.01). However, no consistent effect was found on narcotic calls. Little evidence of displacement of crime control benefits to areas near experimental hot spots was observed.

What were the implications for law enforcement?

The authors suggest that (1) police can be more effective when they take a more specific approach to crime and disorder; (2) the study provides evidence that tailor-made responses to problems can be effective in reducing disorder; and (3) enforcement efforts focused on specific places do not necessarily cause displacement of crime problems to surrounding areas and may lead to a diffusion of benefits.

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