Crime Rates Won’t Work: Analyzing Crime for Small Areas Taking into Account More Than Population

Abstract

Crime rates — numbers of crimes divided by the population living in an area — have problems when used for small areas. Some small areas include substantial nonresidential areas that contribute to the risk of crime, can be the location of crimes, but that have no populations. Negative binomial models to predict counts of the numbers of crimes in small areas are used to incorporate multiple measures of the risk or exposure to crime that cannot be accomplished using crime rates. Population, several measures of employment, and numbers of students in small areas from a transportation planning dataset all contribute to exposure and the prediction of crime in Indianapolis. Because these data are specific to Indianapolis, models using generally available data from the Census Transportation Planning Products and only data from the census of population are evaluated as alternatives. As the initial exposure data were available for the entire metropolitan area, alternative crime rates using these data are estimated and compared with the traditional population-based crime rates for 14 municipalities in the metropolitan area.