Marijuana Regulation and Crime Rates


Adult use marijuana laws are not associated with an uptick overall criminal activity

  • “This review summarizes extant literature on the effect of drug policy liberalization on crime, traffic safety, law enforcement, and racial disparities. … Overall, the literature suggests that cannabis legalization has resulted in some benefits to public health and public safety, even while some studies have produced mixed findings with regard to particular outcomes. … Much of the literature regarding the impact of marijuana legalization on crime shows promising effects, including decreases in violent and property crime, reductions in drug-related arrests, and an improvement in crime clearance rates.”
  • “The legalization of marijuana for recreational use continues to expand across America. Colorado and Washington were the first states to legalize marijuana in 2012. A primary concern regarding legalization is how these policy changes affect crime rates. Researchers have begun to estimate the effect marijuana legalization has had on crime rates. We extend this literature by using a different analytical approach. State level data covering years 2000–2019 were analyzed using the synthetic control method to find that legalizing marijuana for recreational use in Colorado and Washington was generally not associated with variations in index crime rates. These findings substantiate prior research. Increased crime rates should not be a primary concern as more states move to adopt recreational marijuana use legislation.”
  • “Using data covering the period 2000-2019 from a variety of national sources (the National Survey of Drug Use and Health, the Uniform Crime Reports, the National Vital Statistics System, and the Treatment Episode Data Set) this study is the first to comprehensively examine the effects of legalizing recreational marijuana on hard drug use, arrests, drug overdose deaths, suicides, and treatment admissions. Our analyses show that RMLs increase adult marijuana use and reduce drug-related arrests over an average post-legalization window of three to four years. There is little evidence to suggest that RML-induced increases in marijuana consumption encourage the use of harder substances or violent criminal activity.”
  • “This study provides some evidence demonstrating a crime-reducing effect of recreational marijuana legalization in Colorado on neighboring states. Specifically, we observed that the property crime rate and larceny rate experienced substantial decreases in the border counties in neighboring states relative to nonborder counties following the legalization in Colorado. … This finding suggests that recreational marijuana legalization in a state (e.g., Colorado) may not bring about negative consequences on crime in neighboring states, which challenges the assertions made by public officials in these neighboring states arguing a crime-inducing effect of legalization.”
  • “First-pass evidence is provided that the legalization of the cannabis market across US states is inducing a crime drop. We exploit the staggered legalization of recreational marijuana enacted by the adjacent states of Washington (end of 2012) and Oregon (end of 2014). Combining county-level difference-in-differences and spatial regression discontinuity designs, we find that the policy caused a significant reduction in rapes and property crimes on the Washington side of the border in 2013-2014 relative to the Oregon side and relative to the pre-legalization years 2010-2012. The legalization also increased consumption of marijuana and reduced consumption of other drugs and both ordinary and binge alcohol. … The concern that legalizing cannabis for recreational purposes may increase crime occupies a prominent position in the public debate about drugs. Our analysis suggests that such a concern is not justified.”
  • “Our models show no negative effects of legalization and, instead, indicate that crime clearance rates for at least some types of crime are increasing faster in states that legalized than in those that did not. … [T]he current evidence suggests that legalization produced some demonstrable and persistent benefit in clearance rates, benefits we believe are associated with the marijuana legalization proponents’ prediction that legalization would positively influence police performance.”
  • “There is evidence in this table that the legalization of recreational cannabis enacted in Washington caused a decrease in crime rates. The point estimates for rape, assault, robbery, burglary and theft are all negative. This conclusion is reinforced by the statistical significance of the drop in rapes and thefts. … Our estimates reveal that the legalization decreased … both ordinary alcohol and binge alcohol. … These effects on consumption suggest that one of the mechanisms underlying the reduction in crime may be a substitution away from other drugs … such as alcohol, which makes consumers more aggressive than if consuming cannabis.”
  • “Since voters approved Initiative 502, FBI crime statistics show lower rates of violent crime in Washington than before legalization. According to the FBI data, in 2011 there were 295.6 violent offenses reported per 100,000 Washington residents. In 2015, the most recent full year of data available, that rate had fallen to 284.4 violent offenses per 100,000 people.”
  • “[M]onthly crime rates from Denver, Colorado … remain essentially constant after 2012 and 2014. … Other cities in Colorado mirror those findings. … [In Seattle, Washington,] both categories of crime (violent crime and property crime) declined steadily over the past 20 years, with no major deviations after marijuana liberalization. … Monthly violent and property crime remained steady after legalization in Portland, Oregon. … Elsewhere in Oregon, we see no discernible changes in crime trends before and after legalization or medical marijuana liberalization.”
  • “[V]iolent crime and property crime in Denver … dropped 10.6 percent [following legalization] compared to that same span one year earlier.. Homicides have dropped to less than half of last year’s levels, and motor vehicle theft has shrunk by over one-third.”

Adult use legalization laws are associated with improvements in crime clearance rates

  • “Based on Uniform Crime Reports (UCR) data from 2007 to 2017, this study used difference-in-differences (DID) analysis and the synthetic control method (SCM) to examine the effect of recreational marijuana legalization on the clearance rates for multiple types of violent crimes in Oregon (OR), a state that legalized recreational marijuana in late 2014. Results offer some evidence suggesting a beneficial impact of legalization on violent crime clearances, as manifested by significant increases in the clearance rate for overall violent crimes and that for aggravated assault in OR counties relative to those in the non-legalized states following legalization.”
  • “[M]arijuana legalization and sales have had minimal to no effect on major crimes in Colorado or Washington. We observed no statistically significant long-term effects of recreational cannabis laws or the initiation of retail sales on violent or property crime rates in these states. … Our results from Colorado and Washington suggest that legalization has not had major detrimental effects on public safety.”
  • “The goal of this project was to analyze quantitative and qualitative data in 11 targeted states (Arizona, California, Colorado, Idaho, Kansas, Nebraska, Nevada, Oklahoma, Oregon, Utah, and Washington) to address three research questions: 1. what are the impacts of marijuana legalization and decriminalization on criminal justice resources in Colorado, Washington, and Oregon?; 2. what are the impacts on criminal justice resources in states that border the states (Nebraska, Nevada, Oklahoma, Utah, and Kansas) that have legalized marijuana?; and 3. what are the impacts of marijuana legalization and decriminalization on drug trafficking through northern and southwest border states (Arizona, California, Idaho, Oregon, and Washington)? … First, it indeed seems to be the case that legalizing the recreational use of marijuana results in fewer marijuana related arrests and court cases. Whether we look at arrests or court case filings for possession or distribution, marijuanarelated offenses seem to have decreased … since legalization of recreational use. … [W]e saw no evidence that marijuana legalization had an impact on indicators in border states. Marijuana-related arrests and charges did not increase in either the state as a whole or, in the case of Nebraska, in counties that directly border the state that legalized marijuana, after legalization. … [W]e found no indications of increases in arrests related to transportation/trafficking offenses.”

Medical cannabis regulatory laws are not associated with an uptick overall criminal activity

  • “In this paper we attempt to answer the question, does prohibition lead to a reduction in crime? To do so, we take advantage of the growing trend in medical marijuana laws in the U.S. that effectively end federal prohibition of marijuana. We employ a difference-in-differences empirical strategy to exploit natural variation in these laws across states and time. … [W]e estimate significant reductions in violent crime rates in states that legalize medicinal marijuana. Moreover, we find evidence that ending marijuana prohibition results in larger reductions in violent crime rates in states that border Mexico and in urban counties. We also find evidence that medical marijuana legalization reduces property crimes, with larger reductions in states that border Mexico.”
  • “The objective of this study is to investigate whether a particular element of MMLs, namely allowance for dispensaries, affects local crime and other indicators of marijuana misuse. We find no evidence that ordinances allowing for marijuana dispensaries lead to an increase in crime. In fact, we see some evidence of a reduction in property crime. … Our study appears to reinforce the conclusions from other studies that fail to find an increase in the type of crime predicted by law enforcement. We find no effects on burglary, robberies, or assaults, which are the types of crimes one would expect if dispensaries were prime targets as a result of their holding large amounts of cash. … Our findings indicate that policymakers should be careful in how they regulate the presence of dispensaries, while not jumping to the conclusion that dispensaries are clearly crime generating hot-spots. … Our findings suggest that it is possible to regulate these markets and find a common ground between safety and access to medical marijuana.”
  • “[T]he introduction of medical marijuana laws (MMLs) leads to a decrease in violent crime in states that border Mexico. The reduction in crime is strongest for counties close to the border (less than 350 kilometres) and for crimes that relate to drug trafficking. In addition, we find that MMLs in inland states lead to a reduction in crime in the nearest border state. Our results are consistent with the theory that decriminalisation of the production and distribution of marijuana leads to a reduction in violent crime in markets that are traditionally controlled by Mexican drug trafficking organizations.”
  • “We do not find evidence that medical marijuana laws consistently affect violent and property crime. … Our results suggest that liberalization of marijuana laws is unlikely to result in the substantial social cost that some politicians clearly fear.”
  • “The central finding gleaned from the present study was that MML (medical marijuana legalization) is not predictive of higher crime rates and may be related to reductions in rates of homicide and assault, … [R]obbery and burglary rates were unaffected by medicinal marijuana legislation, which runs counter to the claim that dispensaries and grow houses lead to an increase in victimization due to the opportunity structures linked to the amount of drugs and cash that are present. …. [T]his is in line with prior research suggesting that medical marijuana dispensaries may actually reduce crime in the immediate vicinity.”

Retail cannabis facilities are not positively associated with increased criminality, and may play a role in the prevention of certain crimes, like larceny

  • “This paper studies the effects of marijuana legalization on neighborhood crime and documents the patterns in retail dispensary locations over time using detailed micro-level data from Denver, Colorado. … The results imply that an additional dispensary in a neighborhood leads to a reduction of 17 crimes per month per 10,000 residents, which corresponds to roughly a 19 percent decline relative to the average crime rate over the sample period. … Overall, our results suggest that dispensaries cause an overall reduction in crime in neighborhoods, with no evidence of spillovers to surrounding neighborhoods. … Our results are consistent with theories that predict that marijuana legalization will displace illicit criminal organizations and decrease crime through changes in security behaviors or substitution toward more harmful substances. … Lastly, there is no evidence that increased marijuana use itself results in additional crime.”
  • “Tobacco shops, medical marijuana dispensaries (MMD), and off-sale alcohol outlets are legal and prevalent in South Los Angeles, California-a high-crime, low-income urban community of color. This research is the first to explore the geographic associations between these three legal drug outlets with surrounding crime and violence in a large low-income urban community of color. … Results indicated that mean property and violent crime rates within 100-foot buffers of tobacco shops and alcohol outlets-but not MMDs-substantially exceeded community-wide mean crime rates and rates around grocery/convenience stores (i.e., comparison properties licensed to sell both alcohol and tobacco).”
  • “The results presented above show that temporary dispensary closures increase crime in the short-run. … Analyzing medical marijuana dispensary closures in the City of Los Angeles, we find no support for the idea that closing dispensaries reduces crime. Rather, temporary closures deter some types of Part I crime. … Our findings have direct policy implications for regulating marijuana sales in the U.S. They imply that dispensary closures, and potentially the closure of other types of retails establishments, exert a significant negative externality in terms of neighborhood criminality. A quick back of the envelope cost calculation using the change in larceny theft at 1/3 of a mile and crime costs … suggests that an open dispensary provides over $30,000 per year in social benefit in terms of larcenies prevented.”
  • “There were no observed cross-sectional associations between the density of medical marijuana dispensaries and either violent or property crime rates in this study. These results suggest that the density of medical marijuana dispensaries may not be associated with crime rates or that other factors, such as measures dispensaries take to reduce crime (i.e., doormen, video cameras), may increase guardianship such that it deters possible motivated offenders.”