Post on 31-Dec-2015
Imprisonment and Crime: Can Both be Reduced?
Daniel S. Nagin Carnegie Mellon University
National Association of Sentencing Commissions
August 7, 2012
Growth in US Incarceration Rate
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Some Observations About the Four Decade Long Increase in Imprisonment• Undoubtedly reduced crime but size of
reduction is highly uncertain and also irrelevant to policy changes from the status quo
• Social and economics cost have been large • Correction costs have become unsustainable• Wide spread recognition across the political
spectrum that crime policy needs to be re-thought
Imprisonment and Crime: Can Both Be Reduced?
Steven Durlauf and Daniel Nagin(Criminology and Public Policy, 2011)• Yes• Requires a shift from severity-based to
certainty-based sanction policies• Shift in resources from corrections to policing• Focus today will be on severity component of
the conclusion
When Brute Forces Fails: How to Have Less Crime and Imprisonment
by Mark Kleiman
• Reaches broadly similar conclusion
Potential Crime Prevention Effects of Imprisonment
• Incapacitation• Specific Deterrence—Effect of the experience
of imprisonment on reoffending• General Deterrence—Effect of the threat of
punishment on offending
Why Deterrence Is Important to Crime Control Policy
• Crime control by incapacitation necessarily increases imprisonment
• Crime control with deterrence can reduce both crime and imprisonment—if the crime is deterred there is no need for punishment
Key Conclusion of Recent Literature Reviews
• The marginal deterrent effect of increasing already lengthy prison sentences is modest at best.
• Incapacitation effects seem to decline with the scale of imprisonment
• The strategic deployment police has a substantial marginal deterrent effect.
• No evidence of a specific deterrent effect—all evidence points to either no effect or a crime increasing effect of the experience of imprisonment
Research on Sentence Length and Deterrence
• California’s 3-Strikes law at best has had a modest deterrent effect
• Increased penalties upon reaching age of majority have no apparent deterrent effect
• Project Exile (Richmond, VA) no apparent deterrent effect
• Short but certain periods of incarceration do affect the behavior of active offenders
Figure 2: Marginal Versus Absolute Deterrent Effects
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Sentence Length
Policy Implications for Sentencing
• Lengthy prison sentences are not effective deterrents
• Incapacitating aged criminals is not cost effective crime control– Recidivism of releases 45 or older is 45% less than their
18 to 24 counterparts– 17% of California’s prison population is 50 or older, up
from 6% in 1998– Nationally, 20% of prison population is 45 or older,
double 20 years ago– 10% of prison population is serving life terms (4% LWOP)
Bottom line
• Lengthy sentence can not be justified based on crime control grounds—they must be justified on justice grounds
• In an era of tight crime control budgets, policing (and parole and probation services) not prisons should receive a larger share of a smaller pie.
• Need to scale back on sentence length, particularly of the mandatory minimum and lengthy variety
Recent Essays
• Imprisonment and Crime: Can Both Be Reduced?
• Imprisonment and Reoffending• Deterrence: A Review of the Evidence by a
Criminologist for Economists• Deterrence in the 21st Century: A Review of
the Evidence• My email address: dn03@andrew.cmu.edu
Thank youdn03@andrew.cmu.edu