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US Marijuana

Glass containers display varieties of marijuana for sale on shelves at The Station, a retail and medical cannabis dispensary, in Boulder, Colo., Thursday, Aug. 11, 2016. (AP Photo/Brennan Linsley)

As cities and counties like Napa continue to grapple with how best to regulate adult marijuana use, it is important that lawmakers and regulators take into account the experiences from other states.

Specifically, data from Colorado and Washington – both of which enacted similar regulatory schemes in 2012 – provide ample evidence with regard to the health, safety, and economic impacts of these policy changes.

Regulated statewide marijuana markets have provided an economic boost to numerous cities and states – leading to increased tax revenues, tourism, and home values.

A 2017 state-by-state analysis by content provider identified 149,304 full-time jobs in the legal cannabis sector. According to data compiled by, the total number of marijuana industry job posts increased by 445 percent in 2017. Year-over-year growth of job posts in the cannabis industry is outpacing both tech (254 percent growth) and healthcare (70 percent growth).

In Colorado, cannabis-specific taxes and fees have yielded $506,143,635 in state revenue since Jan. 1, 2014 — a total that well exceeds initial projections. Marijuana sales in Washington state continue to grow at a steady rate, with total 2017 sales topping $1.1 billion at the end of September.

At the same time, these laws have not been associated with serious adverse public health consequences. For example, teen marijuana use and access has fallen significantly in recent years, as have opioid-related hospitalizations and mortality in legal states. Data also reports drops in drug treatment admissions, alcohol consumption, and in prescription drug spending.

In Colorado, according to the Department of Public Health, “For adults and adolescents, past-month marijuana use has not changed since legalization either in terms of the number of people using or the frequency of use among users. Based on the most comprehensive data available, past month marijuana use among Colorado adolescents is nearly identical to the national average.”

In Washington, rates of current marijuana use and lifetime marijuana use have fallen among young people post-legalization. According to data released last year by the Washington State Institute for Public Policy, these declines were most pronounced among eigth and 10th graders.

Researchers concluded: “We found no evidence that I-502 enactment, on the whole, affected cannabis abuse treatment admissions. ... [and] we found no evidence that the amount of legal cannabis sales affected youth substance use or attitudes about cannabis or drug-related criminal convictions.”

Equally importantly, concerns regarding potential adverse effects on traffic safety have also not come to fruition. Writing in the August 2017 edition of The American Journal of Public Health, University of Texas researchers compared traffic crash data in the three years prior to the enactment of adult use legalization in Colorado and Washington versus data trends in the three years immediately following legalization.

“We found no significant association between recreational marijuana legalization in Washington and Colorado and subsequent changes in motor vehicle crash fatality rates in the first three years after recreational marijuana legalization,” they concluded.

They further reported, “[W]e also found no association between recreational marijuana legalization and total crash rates when analyzing available state-reported non-fatal crash statistics.”

Investigators also compared traffic safety trends in Colorado and Washington versus eight control states that had not altered their marijuana laws. They concluded, “[C]hanges in motor vehicle crash fatality rates for Washington and Colorado were not statistically different from those in similar states without creational marijuana legalization.”

Let’s be clear — legalization neither creates nor normalizes the marijuana market. This market already exists, though in jurisdictions like Napa it remains largely underground and out of the public’s eye.

The enactment of Proposition 64 is an opportunity for local lawmakers to bring these grey market marijuana-related activities above ground and to regulate them in a manner that is consistent with local values and in accordance with our commitment to public safety.

Paul Armentano is the Deputy Director of the National Organization for the Reform of Marijuana Laws (NORML) and is the co-author of the book Marijuana Is Safer: So Why Are We Driving People to Drink (Chelsea Green Publishing, 2013).