Legalizing recreational marijuana has had minimal effect on violent or property crime rates in Washington and Colorado, a WSU study funded by the National Institute of Justice has found.
"As the nationwide debate about legalization, the federal classification of cannabis under the Controlled Substances Act, and the consequences of legalization for crime continues, it is essential to center that discussion on studies that use contextualized and robust research designs with as few limitations as possible," Dale W. Willits, an assistant professor of criminal justice and criminology at WSU and a study co-author, told the Crime & Justice Research Alliance. "This is but one study and legalization of marijuana is still relatively new, but by replicating our findings, policymakers can answer the question of how legalization affects crime."
Previous studies have reported mixed and inconclusive results. But the new research, published today in the journal Justice Quarterly, uses what are described as more rigorous methods in the evaluation of monthly crime rates as compiled in the FBI's Uniform Crime Reports from 1999 to 2016.
The researchers focused on Washington and Colorado, the first two states in the nation to legalize the growing, processing and commercial sale of cannabis for recreational use, and compared monthly crime rates to those in 21 states where recreational and medicinal marijuana use remains illegal.
The study found no statistically significant long-term effects of recreational cannabis laws, or the initiation of legal retail sales, on violent or property crime rates in either state, though Washington saw a decline in burglary rates. The findings suggest legalization and sales of marijuana have had minimal effect on major crimes in both states.
Although property crime rates in both states, and aggravated assaults in Washington, briefly increased immediately following legalization, the study found it wasn't a permanent shift.
Because the research focused on major crimes, the study's authors note they didn't draw conclusions about other types of offenses such as driving under the influence. Nor does the study rule out the possibility that the effects could be different for some communities at the individual local level.
"In many ways, the legalization of cannabis constitutes a grand ongoing experiment into how a major public policy initiative does or does not accomplish its expected outcomes," said the study's lead author, Ruibin Lu, an assistant professor of criminal justice at Stockton University who began working with the research team while a doctoral student at WSU. "Given the likelihood of more states legalizing recreational marijuana, we felt it was important to apply robust empirical methods to parse out the effects of this action on crime in the first years after legalization."
In addition to Willits and Lu, study authors include WSU researchers, Mary K. Stohr, David Makin, John Snyder, Nicholas Lovrich, Mikala Meize, Duane Stanton and Craig Hemmens, along with Guangzhen Wu from the University of Utah.
