Deterrence and Incapacitation: An Interrupted Time‐Series Analysis of California's Three‐Strikes Law¹

Abstract

Using uniform crime statistics, this research investigates the impact of California's three‐strikes law on instrumental, violent, minor, and drug‐related crimes over the first 5 years of the law's implementation. Autoregressive integrated moving average (ARIMA) models reveal little immediate impact of the law, but significant effects on instrumental crime over time, suggesting an incapacitation effect. After correcting for autocorrelation distortions, less restrictive multiple regression models that test simultaneously for immediate and gradual intervention effects disclose immediate (deterrent) effects on instrumental and minor crimes and arrests, and long‐term (incapacitation) effects on these and violent crimes as well. Drug‐related crimes appear impervious to the three‐strikes law under any analytic model, suggesting the unresponsiveness of such crimes to increasingly severe legal sanctions.

Three-Strikes Legislation

“…Studies of the crime-reduction effects of Three Strikes laws have produced mixed results. Ramirez and Crano (2003) detect few immediate impacts of Three Strikes on crime in California, some deterrence and incapacitation effects over time for violent and premeditated offenses and for "minor" crimes not targeted by Three Strikes, and no impacts on drug offenses. Worrall (2004) finds "virtually no deterrent or incapacitative effects on serious crime."…”

Impacts of ‘Three Strikes and You're Out’ on Crime Trends in California and Throughout the United States

“…Several reports completed in the 1990s and early 2000s include the caveat that sufficient data to measure the law's full impacts on crime might not be available for several years, particularly because the incapacitation effects associated with lengthy mandatory sentences would only be observed after affected offenders completed the sentences they would already have faced in the law's absence (Austin et al, 1999;Greenwood et al, 1994; J. R. Ramirez & Crano, 2003). Now that more than a decade has passed since the law's adoption, sufficient postimplementation data exist to conduct more rigorous analyses.…”

“…Worrall's 2004 study uses a cross-sectional time series model with fixed effects for years and counties to examine Three Strikes' effects using data on California's counties from 1989 to 2000. In contrast to Ramirez and Crano (2003), Worrall's investigation finds that the law has "virtually no deterrent or incapacitative effects on serious crime" once county fixed effects are taken into account (Worrall, 2004). Kovandzic, Sloan, andVieratis (2002, 2004) apply cross-sectional time series analysis to data for 188 cities in the United States from 1980 to 2000.…”

Impacts of “Three Strikes and You're Out” on Crime Trends in California and Throughout the United States

“…Several reports completed in the 1990s and early 2000s include the caveat that sufficient data to measure the law's full impacts on crime might not be available for several years, particularly because the incapacitation effects associated with lengthy mandatory sentences would only be observed after affected offenders completed the sentences they would already have faced in the law's absence (Austin et al, 1999;Greenwood et al, 1994;J. R. Ramirez & Crano, 2003).…”

“…Worrall's 2004 study uses a cross-sectional time series model with fixed effects for years and counties to examine Three Strikes' effects using data on California's counties from 1989 to 2000. In contrast to Ramirez and Crano (2003), Worrall's investigation finds that the law has "virtually no deterrent or incapacitative effects on serious crime" once county fixed effects are taken into account (Worrall, 2004). Vieratis (2002, 2004) apply cross-sectional time series analysis to data for 188 cities in the United States from 1980 to 2000.…”