Marijuana Sale in California
A customer reaches for cannabis products at MedMen in West Hollywood, California, on Jan. 2, 2018. David McNew/Getty Images

What are the ways to reduce crime rates in the United States? Gun control, counseling programs, crackdown on drugs... that list could go on, but you probably didn't think legalizing marijuana.

According to a new study by a three-member team of economists, the introduction of medical marijuana has helped bring down violent crime cases in states that border Mexico.

The study, titled “Is Legal Pot Crippling Mexican Drug Trafficking Organizations? The Effect of Medical Marijuana Laws on US Crime,” said violent crime fell by 13 percent on average in states located on the Mexican border that have legalized medical use of cannabis.

“These laws allow local farmers to grow marijuana that can then be sold to dispensaries where it is sold legally,” said economist Evelina Gavrilova from the Norwegian School of Economics (NHH), one of the authors of the study. “These growers are in direct competition with Mexican drug cartels that are smuggling the marijuana into the U.S. As a result, the cartels get much less business.”

“Whenever there is a medical marijuana law we observe that crime at the border decreases because suddenly there is a lot less smuggling and a lot less violence associated with that,” Gavrilova added.

As part of the study, Gavrilova, along with fellow researchers Takuma Kamada, from Pennsylvania State University, and Floris Zoutman, also of NHH, studied data from the Federal Bureau of Investigation’s uniform crime reports and supplementary homicide records from 1994 to 2012. The team found the effect of marijuana laws was largest in California, which showed a 15 percent reduction in violent crime. The impact was least in Arizona, where there was a fall of just 7 percent.

Among the states bordering Mexico, marijuana laws had most impact on cases of robbery, which fell by 19 percent, and murder, which dropped by 10 percent. The study also showed that homicides not related to drug trade dipped by 41 percent in those states.

Most of the marijuana consumed in the U.S. comes from Mexico, where seven major cartels control the illicit drug trade, the Guardian reported.

The study gains significance at a time when Attorney General Jeff Sessions rescinded a policy Jan. 4 which was enacted by the Obama administration, allowing legalized marijuana to flourish in states without federal interventions.

“When the effect on crime is so significant, it’s obviously better to regulate marijuana and allow people to pay taxes on it rather than make it illegal,” Gavrilova said. “For me it’s a no brainer that it should be legal and should be regulated, and the proceeds go to the Treasury.”

According to the Guardian report, medical marijuana laws are implemented in more than 20 states in the U.S. In these states, there is one marijuana dispensary functioning for every six regular pharmacies.

The study was published in The Economic Journal in November 2017.