NCJ Number
85385
Date Published
1981
Length
14 pages
Annotation
Statistical analysis of crime data for the Boston area indicates that the influence of neighboring enforcement activity on local crime is negligible.
Abstract
Although the Boston area data first appeared to support the hypothesis of crime displacement resulting from neighboring law enforcement activity, further analysis suggested that the results were spurious. Expressing the law enforcement effort measure as a composite differential variable imposes a restriction which is not theoretically grounded, and this results in an estimated coefficient for this variable which is a biased estimate of the simple regression coefficient on local enforcement activity alone. When neighboring enforcement effort was entered separately, it was insignificant and usually had the wrong sign. Correction for multicollinearity and simultaneity bias did not alter these conclusions. At best, the study indicates that displacement effects are too small to be measured with this study's data and methodology. These results are not necessarily totally inconsistent with other studies that report the displacement of crime resulting from law enforcement activity, since these effects tend to be very small. Alternative definitions of neighboring communities or a different formulation of the spillover process may have yielded more positive results for the Boston area. The primary conclusion from the study is that the major deterrent to local criminal activity is law enforcement effort, and the benefits of police consolidation in reducing crime displacement appear minimal. Tabular data and 14 references are provided. (Author summary modified)