TY  - JOUR
AU  - Kessler,Daniel
AU  - Levitt,Steven D.
TI  - Using Sentence Enhancements to Distinguish between Deterrence and Incapacitation
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 6484
PY  - 1998
Y2  - March 1998
UR  - http://www.nber.org/papers/w6484
L1  - http://www.nber.org/papers/w6484.pdf
N1  - Author contact info:
Daniel Kessler
Hoover Institution
Stanford University
434 Galvez Mall
Stanford, CA  94305
Tel: 650/723-0596
E-Mail: fkessler@stanford.edu

Steven D. Levitt
Department of Economics
University of Chicago
1126 East 59th Street
Chicago, IL  60637
Tel: 773/834-1862
Fax: 773/702-8490
E-Mail: slevitt@midway.uchicago.edu
M2  - featured in NBER digest on 1998-10-01
AB  - It is typically difficult to differentiate empirically between deterrence and incapacitation since both are a function of expected punishment.  In this paper we demonstrate that the introduction of sentence enhancements (i.e. increased punishments that are added on to prison sentences that would have been served anyway) provides a direct means of measuring deterrence.  Because the criminal would have been sentenced to prison anyway, there is no additional incapacitation effect from the sentence enhancement in the short-run.  Therefore, any immediate decrease in crime must be due to deterrence.  We test the model using California's Proposition 8 which imposed sentence enhancements for a selected group of crimes.  In the year following its passage, crimes covered by Proposition 8 fell by more than 10 percent relative to similar crimes not affected by the law, suggesting a large deterrent effect.  Three years after the law comes into effect, eligible crimes have fallen roughly 20-40 percent compared to non-eligible crimes.  This large deterrent effect suggests that sentence enhancements, and may be more cost-effective than is generally thought.
ER  -