What Displacement Means for Your POP Project

Crime displacement and diffusion of benefits have many implications for your problem-oriented policing project. Displacement may occur more readily when a response is too narrow in scope, is applied randomly without careful analysis of the problem, or is based on an inaccurate understanding of the problem. Yet, even in these cases, crime or nuisance behavior that is displaced may not be total, and the overall effect may be inconsequential relative to the gains achieved by the response. A well-researched problem-oriented policing project should identify the likelihood of displacement during the analysis phase and should account for it in the formulation of the response. You should determine whether displacement or diffusion of benefits occurs during the assessment phase. It is important to assess the extent to which displacement or diffusion happens because the successes your project achieves can either be undermined by displacement or amplified by diffusion.

When the benefits of your successful problem-oriented policing project are outweighed by the costs, harm, and/or volume of displaced crime, the prevention effort becomes ineffective.27 For this reason, your assessment should measure the extent of crime displacement and compare it to the achieved gains. (How to do this is presented in a following section of this guide.) Being alert to the possibility of diffusion of benefits is also important when evaluating your project because determining your response's overall effectiveness is affected by an assessment of possible diffusion effects. Questions you need to answer are:

• What were the program's effects on the targeted behaviors in the response area?
• Was there any displacement? If so, what was the extent of the displacement? What was the extent of the harm produced by the displacement?
• Did the program have any positive effects in areas other than the response area (e.g., diffusion of benefits)? If so, to what extent?

Not assessing for diffusion could result in a conclusion of only marginal gains (when a response achieved only this much); whereas inspecting and observing the possibility of diffusion could lead to more favorable conclusions of effectiveness. The remainder of this guide presents things you should think about to manage displacement if it occurs, how to better understand your local displacement potential, and how to measure it so you can better assess your project's impact.