Is Crime Contagious?
Jens Ludwig and Jeffrey R. Kling
The Journal of Law and Economics August 2007, Vol. 50, No. 3: 491-518.

Understanding whether criminal behavior is “contagious” is important for law enforcement and for policies that affect how people are sorted across social settings. We test the hypothesis that criminal behavior is contagious by using data from the Moving to Opportunity (MTO) randomized housing mobility experiment to examine the extent to which lower local area crime rates decrease arrest rates among individuals. Our analysis exploits the fact that the effect of treatment group assignment yields different types of neighborhood changes across the five MTO demonstration sites. We use treatment by site interactions as instruments for measures of neighborhood crime rates, poverty, and racial segregation in our analysis of individual arrest outcomes. We are unable to detect evidence in support of the contagion hypothesis. Neighborhood racial segregation appears to be the most important explanation for across-neighborhood variation in arrests for violent crimes in our sample, perhaps because drug market activity is more common in high-minority neighborhoods.

Heavy Alcohol Use and Crime: Evidence from Underage Drunk-Driving Laws
Christopher Carpenter
The Journal of Law and Economics August 2007, Vol. 50, No. 3: 539-557.

This paper provides new evidence on the causal effect of alcohol use and crime. I use variation induced by the adoption of strict zero-tolerance (ZT) drunk-driving laws, which significantly reduced binge drinking by males aged 18–20 years but did not affect slightly older males aged 22–24 years. I use age-specific arrest data for police agencies in metropolitan statistical areas to estimate the effect of ZT laws on crime, controlling for both year and police agency fixed effects. I find that ZT laws significantly increased the fraction of adult male arrests for driving under the influence attributable to 18–20-year-olds and decreased the fraction of nuisance and property crime arrests attributable to 18–20-year-olds, with no effects on violent crime. These results are validated by important null findings: ZT laws did not affect arrests in any crime category for males aged 22–24 years. These results suggest that heavy alcohol use causes the commission of property and nuisance crimes.