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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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