The Importance of Place in Policing - Empirical Evidence and Policy ...

prevention effect. The Campbell systematic review described aboveexamined displacement data for five of the nine studies, finding thatnone reported substantial immediate spatial displacement of crimeinto areas surrounding the targeted locations (Braga, 2001, 2005,2007).While much attention has been paid to the idea of displacement,methodological problems associated with its measurement haveoften been overlooked (Weisburd & Green, 1995b; for exceptionssee Barr & Pease, 1990 and Pease, 1991). This is not to say thatdisplacement has not been studied; only that empirical examinationsof displacement or diffusion have been a byproduct of the study ofsomething else. Typically, knowledge of displacement or diffusionhas been gained from a study that was primarily about the effects ofan innovative crime prevention program. The problem is that astudy that is designed to measure direct program effects will likelyface significant methodological problems in measuring displacementor diffusion (Weisburd & Green, 1995b).A recent study by Weisburd and colleagues (2006) of hot spotspolicing interventions at drug and prostitution markets explicitlyexamined spatial displacement and diffusion as a primary outcomeand presents important insights about why crime does not simplymove around the corner as a response to targeted policing efforts atcrime hot spots. To examine displacement and diffusion effects, awealth of data was collected in the intervention target areas andsurrounding catchment areas, approximately two blocks surroundingeach target area. The study employed analyses of more than6,000 20-minute social observations at the research sites, supplementedby interviews with arrestees from the target areas and ethnographicfield observations.Quantitative findings indicated that for the crime hot spots examined,crime did not simply move around the corner in response tointensive police crime prevention efforts at places. Indeed, the studysupported the position that the most likely outcome of such focusedcrime prevention efforts is a diffusion of crime control benefits tonearby areas. This is illustrated in Figure 8, which documents observedprostitution events in the target and displacement catchmentareas during the period of the study. Here, as in other analyses conductedby Weisburd et al. (2006), crime did not go up in the catchmentareas after there were strong crime prevention gains at thetarget site. Indeed, the catchment areas followed a similar pattern tothe target site, suggesting a diffusion of crime control benefits.43