The Growth of Illicit Drug Use and Its Effects on Murder Rates.

After years of reductions in the rate of murder in the United States, the national murder rate has increased since 2015. The causes of this trend are generally unknown, though there is some evidence related to narcotic drugs. Arrests related to heroin and cocaine had been stable between 2010 and 2014 before a sudden increase in 2015. Likewise, the number of murders related to narcotic drugs has increased since 2013, with a jump in 2015. Increased rates of these crimes parallel recent dramatic growth in overdoses involving heroin. However, the causal relationship between the recent opioid crisis and the rise in murder rates is missing from the literature. I used OxyContin reformulation as an exogenous shock to illicit markets. OxyContin reformulation led some people who misused OxyContin to switch to illicit opioids. Previous work has shown that areas with higher rates of OxyContin misuse experienced faster growth in heroin overdoses post-reformulation. I tested whether this growth in illicit drug use caused an increase in crime. After reformulation, I find significantly greater relative increases in murder rates in states with high pre-reformulation rates of OxyContin misuse. The results support a causal link between the opioid epidemic and crime.