Law enforcement and other opponents of marijuana legalization have long warned that ending prohibition would lead to surges in crime, wreaking havoc on neighborhoods that hosted retail stores and spilling into neighboring states that wanted nothing to do with the drug. But as researchers crunch the data since Colorado and Washington State because the first two states to pass adult-use marijuana laws in 2012, they’re finding scant evidence to support the dire warnings.
One of the latest studies to examine before-and-after crime data, which looked at how legalization in Washington and Colorado affected crime rates in neighboring states, finds that passage of adult-use cannabis laws may have actually reduced certain major crimes in nearby jurisdictions.
“We did not detect any increases in the rates of multiple types of crimes in border counties of the nonlegalized states bordering Colorado and Washington,” wrote the authors of the new study, published in the Journal of Drug Issues. Moreover, “we observed a substantial reduction in certain types of crimes, namely, property crime, larceny, and simple assault, in border counties in the Colorado region.”
“Overall, the results for the Colorado region provide some evidence suggesting a crime-reducing effect of legalization on neighboring states.”
“This finding,” the authors add, “challenges the argument made by the opponents of legalization that marijuana legalization would increase crime.”
The research was conducted by Guangzhen Wu of the University of Utah, Francis D. Boateng of the University of Mississippi and Texas-based economic and statistical consultant Thomas Roney.
Existing research on how cannabis affects crime is limited and largely mixed, the authors write. On one hand, there exists what researchers called “substantial evidence” suggesting that legalizing cannabis increases certain criminal activities. Some studies, for example, have found that neighborhoods with a higher rate of retail marijuana outlets experienced higher rates of crime. Another found that both medical and adult-use marijuana retailers were linked to increases in certain crimes.
Confusing that data, however, is the fact that cannabis businesses typically lack access to traditional banking services, forcing most transactions to be handled in cash. “As scholars have reasoned, the criminogenic effect of recreational marijuana dispensaries is largely attributable to the fact that marijuana sale is a cash-and-carry business,” the study says, “which exposes both the business and customers to criminal victimization.”
Meanwhile, other researchers have argued that legalization in fact reduces crime. They assert not only that decriminalization of cannabis itself reduces crime, but also that legalization shrinks what the study describes as “the underground marijuana market that is believed to be fertile soil for violent crime.” Certain studies support that claim, for example research showing drops in rape and property crime in Washington state compared to neighboring Oregon after Washington legalized marijuana for adults.
Little research has been done, however, into how legalization affects crime rates in nearby states. To answer that question, the team dug into county-level data in neighboring states before and after Washington and Colorado legalized marijuana.
“Border counties in the Colorado region saw substantial decreases in overall property crime rate and larceny rate relative to nonborder counties following Colorado’s legalization.”
Researchers drew data from a variety of sources, but a key source was the Federal Bureau of Investigation’s Uniform Crime Reporting (UCR) program, which tracks a variety of crime statistics. “The UCR data provide not only crime information on most serious violent and property crimes, categorized as Part I crimes, including robbery, aggravated assault, burglary, larceny, and motor vehicle theft, but also less serious crimes such as simple assault, categorized as Part II crimes,” the study says, capturing many of the crimes critics have warned might accompany legalization.
The team controlled for demographic changes, such as population, poverty level, household income and unemployment rate, because of those variables’ strong association with crime rates. They also attempted to control for other changes, such as nearby Oregon and Nevada passing adult-use marijuana laws in 2014 and 2016, respectively.
Analyzing the data, the researchers found no significant changes to crime rates in nonlegal counties bordering Washington following marijuana legalization, refuting the idea that legalization might lead to a spillover of crime to neighboring states.
Data from the Colorado region went further, suggesting “a crime-reducing effect of recreational marijuana legalization in Colorado on neighboring states.”
“In the six states surrounding Colorado—Kansas, Nebraska, New Mexico, Oklahoma, Utah, and Wyoming—following Colorado’s legalization, the border counties experienced, on average, a decrease of 393.1 cases of property crime and 277.3 cases of larceny per 100,000 population relative to the nonborder counties.”
“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,” the study says. “This is also true for the rate of simple assault…if Utah is not considered (only considering Kansas, Nebraska, New Mexico, Oklahoma, and Wyoming as neighboring states of 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,” the researchers concluded.
What might be causing the decreases in crime? Researchers can only speculate. One idea is that lower marijuana prices in legal states “would arguably reduce individuals’ motivation to resort to predatory crime to support their drug use,” the study says. Another is that police may be more alert to cannabis-related crimes in counties close to where cannabis is legal. It’s also possible that easier access to marijuana has led to lower rates of alcohol consumption, the authors said, “which may reduce crime given the well-documented connection between alcohol use and criminal involvement.”
While the study’s findings contradict arguments by some public officials that legalization in a neighboring state might hurt communities at home, researchers caution that they also can’t say with certainty that legalization reduces crime. Counties neighboring Washington, after all, showed no such effect.
“This suggests the potential spillover effect of legalization (either exacerbating or reducing crime in neighboring states, may be a function of the differential social/cultural and policy contexts of the neighboring states,” the authors conclude, “which certainly deserves further scholarly exploration.”