Ohio Issue 2: How is recreational marijuana legalization working in other states?

On Nov. 7, Ohio could join 23 other states as the latest to legalize recreational marijuana, but some say it's difficult to judge how legalization has worked across the nation.

If passed in Ohio, Issue 2 would:

• Allow adults age 21 and older to buy and possess 2.5 ounces of cannabis and 15 grams of concentrates.

• Allow Ohioans age 21 and older to grow up to six plants individually and no more than 12 in a household with multiple adults.

• Tax products 10%, with revenue going toward administrative costs, addiction treatment programs, municipalities with dispensaries and a social equity and jobs program.

More: What Ohioans need to know about November ballot issue to legalize recreational marijuana

It is difficult to measure the impact of marijuana legalization across the country, said Doug Berman, executive director of the Drug Enforcement and Policy Center at Ohio State University. Researchers have conducted studies on marijuana legalization, but different factors make it difficult to reach conclusions.

Berman said in a state like Colorado, which was the first to legalize recreational marijuana, people visited to enjoy what could be called “pot tourism.”

“That necessarily changed the population − the population driving, the population involved in activities of all sorts − that if you were studying the first year after legalization, (it) might look very different than year two, or year three, or year five," Berman said.

But that doesn't mean the studies are incorrect, Berman said: "It means there's so many kinds of elements trying to be studied here. It's really hard to pinpoint how marijuana legalization changes things, especially because we're talking about a substance that's already in the community to a degree we're not even sure of before legalization."

Here’s what some of the research says on how recreational marijuana has been implemented other states.

Marijuana impact on driving, road safety

Ohio Gov. Mike DeWine and other opponents of Issue 2 have raised concerns about legalizing recreational marijuana, and one of the main issues has been the potential impact on traffic safety.

According to a Justice Research and Statistics Association study, an Oregon law enforcement reported a 55% to 60% increase in marijuana-related DUIs.

Michigan State Police’s 2022 Statewide Traffic Crash Data Year End Report said the total number of drug and alcohol involved fatalities decreased by one between 2017, pre-legalization, and 2022, post-legalization, with 421 in 2017 and 420 in 2022.

“A lot of people report using cannabis as a substitute for other drugs or for alcohol, and cannabis studies have shown it is not as associated with risk taking, so if somebody's using cannabis instead of alcohol, they're less likely to drive under the influence in the first place because they're less likely to take risks,” said Karen O’Keefe, director of state policies for Marijuana Policy Project.

Research from the Insurance Institute for Highway Safety said the combined effect of legalization and retail sales was a 5.8% increase in injury crash rates and a 4.1% increase in fatal crash rates.

“If you look at the pattern of other states that have legalized, fatal crashes go up and injury crashes go up by what is increasingly clear is a predictable rate,” said Scott Milburn, a spokesman for Protect Ohio Families, the coalition opposing Issue 2. “And if you apply that rate to Ohio, you see 48 more fatal crashes and 2,300 more injury crashes.”

The illicit market and crime

One study from the Journal of Economic Behavior & Organization found that after marijuana legalization in Washington, rapes dropped by approximately between 15% and 30%, and property crimes fell by between 10% and 20%.

Researchers have also examined how recreational marijuana affected other crime rates.

Right around the time of legalization, crime trends seemed to increase for violent crime for both Colorado and Washington, according to a study by Police Quarterly.

“We've seen the post-legalization in both Colorado and Washington that there was an increase in clearance rates for other crimes,” O’Keefe said. “That could be because police had more time available to solve the crimes. It could be because people were perhaps more likely to talk to the police because they didn't have to be afraid that they weren't cannabis consumers, but they could be wrongfully arrested for it.”

Marijuana and the workplace

In Colorado and Washington, the marijuana positive test rate increased in the workplace by 14% and 16% respectively between 2013 and 2014.

During that time, Colorado's marijuana positivity rate increased from 2.30% to 2.62%, and Washington's marijuana positivity rate increased from 2.38% to 2.75%, according to a study by Quest Diagnostics.

An article by Bloomberg Law, says in some states, like New York, employers are prohibited from testing current and prospective employees. Nevada prohibits job denial based on a positive cannabis test result.

A study from the National Bureau of Economic Research found there can be an increase in workplace performance for adults ages 42 to 60 who are provided with another option to manage chronic pain.

Minor use and access

For those ages 12 to 20, a study from PLoS One found that recreational cannabis legalization did not increase underage cannabis use.

“We know that adult use markets are the best way to keep marijuana out of the hands of kids because in a regulated market, you got to be 21 to buy marijuana,” Haren said.

In a research letter from JAMA Pediatrics, the evidence on effects of recreational marijuana use on youth is mixed. It found there was an increase in marijuana use among eighth to tenth graders after recreational legalization in Washington. The same authors found no evidence of an association between legalization and adolescent use in Colorado.

The CDC’s data on teen cannabis use can be used to compare use for pre-legalization and post-legalization. For example, O'Keefe pointed out that in Michigan, 23.7% of high school students reported having used marijuana in the past 30 days in 2017, but dropped to 14.4% in 2021.

Effects on health

In Colorado, marijuana-related emergency room visits rose for youth ages 13 to 20 between 2005 and 2015, according to an article by Reuters Health.

Another study from JAMA Pediatrics found the mean rate of marijuana-related visits to children's hospitals increased between the two years prior to and the two years after legalization in Colorado.

Data from the National Survey on Drug Use and Health found legalization of marijuana in Washington caused an increase in the consumption of cannabis, and a decrease in the consumption of other drugs and alcohol.

“Every study is giving us a perspective on what that research has revealed about these sets of issues at that particular moment,” Berman said. “But to me, this is an area in which it's really critical to have a wide range of studies and to look at all the patterns as best you can before you can draw any super firm conclusions, either about problems or about benefits.”

Kayla Bennett is a fellow in the E.W. Scripps School of Journalism's Statehouse News Bureau.

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This article originally appeared on The Columbus Dispatch: Ohio Issue 2: How marijuana legalization is working in other states