U.S. flag

An official website of the United States government, Department of Justice.

NCJRS Virtual Library

The Virtual Library houses over 235,000 criminal justice resources, including all known OJP works.
Click here to search the NCJRS Virtual Library

Prison Population Growth and Crime Reduction

NCJ Number
149263
Journal
Journal of Quantitative Criminology Volume: 10 Issue: 2 Dated: (June 1994) Pages: 109-140
Author(s)
T B Marvell; C E Moody Jr
Date Published
1994
Length
32 pages
Annotation
This paper outlines the problems with using the lambda, the individual crime rate of inmates or arrestees, for estimating the impact of State prison populations on crime and reanalyzes and adjusts the widely divergent lambdas from past research to estimate the impact of incapacitation.
Abstract
The result is an uncertain estimate of 16 to 25 index crimes averted per year for each additional prisoner. Regression analysis can provide a better estimate of the impact of prison population growth. Applying the Granger test to pooled State data over 19 years, the analysis reveals that prison population growth leads to lower crime rates but that crime rate changes have little or no short- term impact on prison population growth. A further analysis, in which crime rates were regressed on prison population, includes that, on average, at least 17 index crimes are averted for each additional prisoner. This impact is limited mainly to property crime. Footnotes, tables, and 78 references (Author abstract modified)