Spatial displacement and diffusion of benefits among geographically focused policing initiatives

Abstract

One of the most common criticisms of spatially focused policing efforts (such as Problem-Oriented Policing, police 'crackdowns' or hotspots policing) is that crime will simply relocate to other times and places since the ―root causes‖ of crime were not addressed. This phenomenon—called crime displacement—has important implications for many policing projects. By far, spatial displacement (movement of crime from a treatment area to an area nearby) is the form most commonly recognized. At the extreme, widespread displacement stands to undermine the effects of geographically focused policing actions. More often, however, research suggests that crime displacement is rarely total. On the other end of the displacement continuum is the phenomenon of ‗diffusion of crime control benefits‘ (a term coined by Ron Clarke and David Weisburd in 1994). Diffusion occurs when reductions of crime (or other improvements) are achieved in areas that are close to crime prevention interventions, even though those areas were not actually targeted by the intervention itself. Objectives: To synthesize the evidence concerning the degree to which geographically focused policing initiatives are related to spatial displacement of crime or diffusion of the crime control benefits. Main results: The main findings of the meta-analysis suggested that on average geographically focused policing initiatives for which data were available were (1) associated with significant reductions in crime and disorder and that (2) overall, changes in catchment areas were non-significant but there was a trend in favour of a diffusion of benefit. For the weighted displacement quotient analyses, the weight of the evidence suggests that where changes are observed in catchment areas that exceed those that might be expected in the absence of intervention, a diffusion of crime control benefit rather than displacement appears to be the more likely outcome. The results of the proportional change analysis suggest that the majority of eligible studies experienced a decrease in crime in the treatment area indicating possible success of the scheme. The majority also experience a decrease in the catchment areas suggesting the possibility of a diffusion of benefit. These findings, which could not be statistically tested, are consistent with all others reported here, and with those from the narrative review.