Compare methods

	Crime Displacement and Diffusion Analysis	Near-Repeat Analysis
Field	Criminology	Criminology
Family	Process / pipeline	Process / pipeline
Year of origin	2003	2003
Originator	Kate Bowers & Shane Johnson	Michael Townsley, Shane Johnson & Kate Bowers
Type	Quasi-experimental spatial impact assessment of crime prevention	Space-time clustering test for crime contagion
Seminal source	Bowers, K. J., & Johnson, S. D. (2003). Measuring the geographical displacement and diffusion of benefit effects of crime prevention activity. Journal of Quantitative Criminology, 19(3), 275–301.	Townsley, M., Homel, R., & Chaseling, J. (2003). Infectious burglaries: A test of the near repeat hypothesis. British Journal of Criminology, 43(3), 615–633.
Aliases	Crime Displacement Analysis, Diffusion of Benefits Analysis, Weighted Displacement Quotient, WDQ Analysis	Near Repeat Calculator Method, Space-Time Near-Repeat Analysis, Near-Repeat Victimization, Contagion Crime Pattern Analysis
Related	4	4
Summary	Displacement and diffusion analysis evaluates what happens around a crime-prevention intervention: does crime simply move to nearby areas, times, or targets (displacement), or do the benefits spill over so that crime also falls in surrounding untreated areas (diffusion of benefits)? Bowers and Johnson's weighted displacement quotient (WDQ) provides a simple, widely used metric that compares pre/post crime change in a target area, a surrounding buffer, and a control area.	Near-repeat analysis tests whether crimes cluster in space and time beyond chance: after a crime occurs, are nearby locations at elevated risk for a short period? Developed in the early 2000s by Townsley, Johnson, Bowers and colleagues for burglary, it formalizes the 'contagion' or 'communicable disease' pattern of crime using a Knox space-time test against a Monte Carlo reference distribution.