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Is Crime Seasonal?

NCJ Number
Date Published
January 1984
This report reviews analytical issues that researchers must address when investigating fluctuations in crime and then uses data from the Illinois' Statistical Analysis Center to examine seasonality in crime types, geographic areas, and time periods.

Any discussion of seasonal changes in crime must be qualified by several considerations: the place, the crime's conceptual and operational definitions, circumstances relating to public or private crime, and numerical aspects of the series that would increase the likelihood of significant results. Specifically, researchers should look at the length of the data series; whether local, State, or national level data are appropriate; and whether the crime occurs seasonally or is reported seasonally. The report summarizes findings on the seasonal fluctuations in homicide, rape, aggravated assault, robbery, burglary, theft, and auto theft. Seasonal fluctuations for most types of homicides appear too weak to affect practical administrative decisions. The report suggests that robbery and assault do not vary seasonally, but that less serious crimes of this type are reported to the police more frequently in the summer months. Data show burglary to be strongly seasonal in New York City and the United States as a whole, but not in Chicago. Of all the crime types analyzed, Index larceny/theft seems to have the most consistent seasonal pattern. Seasonal fluctuation or lack of fluctuation may provide clues to the ways a crime is defined, data collection methods, and recordkeeping processes. An annotated bibliography of published and unpublished works on seasonality from the 1960's to the present is provided.

Date Published: January 1, 1984