Legal marijuana: What can Minnesotans expect?

From tomorrow, recreational marijuana will be legal in Minnesota. Center of the American Experiment has never taken a position on the legalization of marijuana — we neither support the measure, nor do we oppose it — but now that it is a done deal, what does the research and data indicate that Minnesotans can expect?

In 2021, the Cato Institute produced a paper titled The Effect of State Marijuana Legalizations: 2021 Update, which is a useful guide to the empirical literature and data to that point. The authors noted that:

Supporters and critics make numerous claims about state‐​level marijuana legalizations. Advocates suggest that legalization reduces crime, raises tax revenue, lowers criminal justice expenditures, improves public health, increases traffic safety, and stimulates the economy. Critics argue that legalization spurs marijuana and other drug or alcohol use, increases crime, diminishes traffic safety, harms public health, and lowers teen educational achievement.

“To determine the effects of legalization and other policy changes on marijuana use,” the authors explain, “we examine the trends before and after the changes.” Specifically:

The specific statewide legalizations we consider are Colorado (2012), Washington (2012), Oregon (2014), Alaska (2014), California (2016), Nevada (2016), Maine (2016), Massachusetts (2016), Vermont (2018), Michigan (2019), and Illinois (2020).

Our analysis examines whether the trends in marijuana use and related outcomes changed substantially after these dates. We consider trends in alcohol and drug use, suicides, crime, traffic fatalities, and economic conditions.

Marijuana and Other Substance Use

The authors note that opponents of marijuana legalization argue that it will lead to increased consumption, especially among youths. Looking at the data, they note that:

Use in states where marijuana is legal tends to be higher than use in the United States overall, but this difference mainly pre‐​dates legalization…

Legalizing states display higher and increasing rates of use prevalence, but these patterns existed prior to legalization.

The available data show no obvious effect of legalization on youth marijuana use.

Opponents have also argued that legalization of marijuana will lead to the increased consumption of other, more dangerous drugs like cocaine. Supporters of legalization, on the other hand, have argued that it will increase consumption of safer drugs like alcohol, in a sort of “substitution effect.” The authors note:

These data suggest no clear relationship between marijuana legalization and cocaine use.

These data show no clear relationship between marijuana legalization and alcohol use.

The claims of neither opponents nor supporters have, then, been borne out.

Health and Suicides

The authors note that supporters of legalization highlight benefits arising from its medicinal possibilities, including towards mental health, while opponents stress other research which runs counter to this, especially with regard to mental health.

The authors find that “It is difficult to see any association between marijuana legalization and changes in suicide trends,” once again pouring cold water on the claims of both supporters and opponents.


Opponents of legalization have argued that increased marijuana use will lead to increased crime, while supporters have argued that it will reduce it by making an illegal activity legal.

To the disappointment of both groups, once again, the authors find that “Overall, violent crime has neither soared nor plummeted in the wake of marijuana legalization.”

Road Safety

Opponents of legalization have argued that increased consumption of marijuana will make the roads less safe. Supporters, by contrast, have argued for the substitution effect again, so that drink drivers will switch to marijuana which, it is argued, impairs you to a lesser extent.

Looking at data for “the difference in driving fatalities between the 11 states included in this policy analysis and the U.S. average, relative to the year of legalization, measured in fatalities per 100 million vehicle miles traveled,” the authors find that “In most states, this trend remained relatively flat post‐​legalization.” Again, support for the claims of neither side can be seen in this data.

Economic Outcomes

Supporters of legalization have argued that it might provide economic benefits by attracting new, especially younger, residents.

However, looking at “the difference between the Case‐​Shiller Home Price Indices for major cities in legalizing states (Denver; Seattle; Portland, Oregon; San Francisco and Los Angeles; Las Vegas; Detroit; Chicago; and Boston) and the national average,” the authors find that:

Only Portland displays any upward trend post‐​legalization. Whereas some people may have moved across state lines for easier access to legal marijuana, any resulting growth in population has been small and is unlikely to cause noticeable increases in housing prices or total economic output.

Supporters have also claimed that legalization “boosts economic activity by creating jobs in the marijuana sector, including ‘marijuana tourism.'”

The authors look at “state employment to population ratios compared with the national average” and find that:

…states that legalized marijuana experienced no discernable change in employment after legalization…Marijuana production and commerce do employ many thousands of people, but the employment gains seen in the wake of legalization are still modest compared with the overall size of each state’s workforce.

Once again, the claims of supporters are not borne out.

Budgetary Impacts

The authors find the only area where marijuana legalization has a “significant impact” is through increased state tax revenue. They do note that “The tax revenues in these states, however, may moderate as more states legalize marijuana.”


Overall, the authors find that:

The data so far…provide little support for the strong claims about legalization made by either opponents or supporters; the notable exception is tax revenue, which has exceeded some expectations.

They do add one important caveat:

…our assessments of legalization’s effects remain tentative because of limitations in the data. The existing data nevertheless provide a useful perspective on what other states should expect from legalization or related policies.

This review of the research and data does not tell us what will happen in Minnesota starting tomorrow, but such a review is necessary for the making of good policy.