Crime concentrations at micro places: A review of the evidence

Chapter 4 reports on a systematic review of crime concentration studies over the last 35 years. We identify 47 papers that report on crime concentrations at a microgeographic unit of analysis. These papers produced 49 estimates of general crime concentration for crime incidents at street segments for a specific cumulative proportion of crime. The median concentration for these estimates is 50% of crime found at 4.5% of streets, and 25% of crime at 1.25% of streets. The bandwidth for 50% crime concentration is 9.3% (1.7 to 11.0%), and for 25% crime concentration 3.0% (0.4 to 3.4%). Using the interquartile range to exclude outliers, we found a bandwidth of 2.5% (3.2 to 5.7%) for 50% of crime, and 1.4% (0.8 to 2.2%) for 25% of crime. Crime concentration was generally stronger for specific types of crime, and bandwidths of concentration were generally smaller. Using alternative measures of crime and different micro geographies produces similar conclusions regarding strong crime concentration at place with narrow bandwidths. Our review shows that a general framework of a law of crime concentration applies across a large number of cities across many regions around the world.