local crime rates. We assess the effects of a recent reform in California that caused a sharp and permanent reduction in the … violent crime and evidence of modest effects on property crime, auto theft in particular. These effects are considerably … considerably lower. We corroborate theses cross-county results with a synthetic-cohort analysis of state crime rates in California …

We study peer effects in crime by analyzing co-offending networks. We first provide a credible estimate of peer effects … criminal from each network that reduces total crime by the largest amount. Using longitudinal data, we are able to compare the … disappeared over time, we show that the theoretical predicted crime reduction is close to what is observed in the real world. We …