Several techniques have been used to estimate effect of police activities on incidence of crime: (1) cross-sectional analysis of reported crime rates compared with resources devoted to police functions, (2) longitudinal analysis of a time series of crime incidence where police deployment or operations changed over time, and (3) experimental manipulation of police activities. Nearly every study has one or more faults, such as failure to distinguish between true and reported crime rates, failure to specify or maintain the experimental conditions, apparent errors in the data, or confusion between cause and effect. This review indicates that most studies are consistent with the view that a substantial increase in police activity will reduce crime for a period of time, but in the real world increases in police manpower tend to follow increases in crime. The magnitude and duration of deterrence effects are essentially unknown.
This report is part of the RAND Corporation Paper series. The paper was a product of the RAND Corporation from 1948 to 2003 that captured speeches, memorials, and derivative research, usually prepared on authors' own time and meant to be the scholarly or scientific contribution of individual authors to their professional fields. Papers were less formal than reports and did not require rigorous peer review.
This document and trademark(s) contained herein are protected by law. This representation of RAND intellectual property is provided for noncommercial use only. Unauthorized posting of this publication online is prohibited; linking directly to this product page is encouraged. Permission is required from RAND to reproduce, or reuse in another form, any of its research documents for commercial purposes. For information on reprint and reuse permissions, please visit www.rand.org/pubs/permissions.
The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.