Medical Marijuana: What we know, what we don’t

Relevant research for considering a potential Wisconsin medical marijuana bill

The Badger Institute launched a first-of-its-kind initiative in late 2023 to better understand the impact of both adult recreational and medical cannabis legalization in other states and provide the citizens of Wisconsin with a research-backed estimate of what the impact could be here.

We have already published multiple installments in this series. More are coming. Here, we summarize the relevant findings thus far related to medical marijuana given the arrival of legislation that would allow its use.

The legislation was outlined by Wisconsin Assembly Republicans in January. The bill, AB1040, would limiting cannabis to individuals certified by doctors as suffering from specific illnesses, and permitting them to buy only smokeless forms of the drug through five state-run dispensaries.

The direct application of our findings to the potential impact of such legislation in Wisconsin is tenuous, given the likely differences between the market proposed and those established by other states. For example, none of the research we have completed analyzes the different impact state-run retail stores may have on any of these factors.

This page will be updated with additional findings as we continue to publish additional research and reports on the impact of legalization.

Public Safety 

Research on states that have fully legalized recreational — that is, adult use — cannabis shows a tradeoff: An overwhelming finding of higher traffic fatalities and, by the weight of the evidence, either no increase and possibly a decrease in statewide crime rates.

But when you focus solely on the research related to medical cannabis legalization, you do not see that same tradeoff.

• Medical cannabis legalization in other states has had either no impact or a positive impact on property and violent crime statewide. 
• The establishment of medical cannabis dispensaries in other states, a step distinct from but usually occurring at the same time as medical legalization, appears to increase crime in that local neighborhood, particularly property and disorder crime.  
• Establishing a medical cannabis market will likely reduce traffic fatalities but will – at worst – have no impact on road safety.  

Read more: Marijuana legalization and the impact on public safety (November 2023)

Workforce

Limited available research shows that medical legalization might have positive benefits for a state’s overall economy and for employment.  

• Legalizing medical use of cannabis in a state increases the labor force participation of certain groups of individuals.  
• Medical cannabis legalization has caused a small reduction in workers’ compensation costs.  

Unlike adult-use legalization, the limited nature of existing research does not give us the ability to understand how medical use access will impact unemployment or disability claims at this time. 

Read more: Marijuana legalization’s workforce impact looks positive (January 2024)

Cannabis Use

We know from our first report that more than 830,000 Wisconsinites use cannabis every year. The number of adults who do so has been increasing in recent years, while the number of minors doing so has declined to its lowest point in the past decade. The available research shows that a move to legalize medical cannabis will likely not disrupt the downward trend in youth use but will accelerate the trend we see in adult use.  

• Allowing the medical use of cannabis in a state will increase adult use of the substance.  
• A policy that only allows medical sales and use of cannabis appears to either have no impact or reduce teen use. 

Read more: What research shows about marijuana legalization and rates of use (December 2023)

Addiction & Other Substance Use

We found in our prior report that the legalization of cannabis for medical use increases use of the substance. Does that result in increased use of other drugs and addiction because of the frequently cited gateway effect of cannabis?

Here is what we do know: 

• The impact of medical cannabis legalization on cannabis use disorder is unclear given an equal split in the findings from research.
• Allowing the medical use of cannabis reduces the use of opioids. 
• The research also appears to indicate that it is likely to reduce the use of other illicit drugs among adults. 

We still do not have the necessary research to draw strong conclusions on the impact such a policy might have on the consumption of alcohol and tobacco. 

Read more: Legalizing cannabis likely means more disordered, harmful use, other states show (February 2024)

Tax Revenue

Research on the topic of taxation reveals that there is a direct relationship between the tax burden states impose on legal marijuana products and the size of the state’s illicit market.

Here is what we know specifically about medical marijuana and taxes:

• 19 out of the 38 states with medical cannabis legalization do not impose a tax on cannabis products intended for medical use.  
• The states that do impose a tax on the medical use of cannabis earn approximately $287 million annually in tax revenue.

Read more: Tax rates, state revenue and markets for marijuana (July 2024) 

Potency

The potency of cannabis products is much higher today than just a few decades ago. Consumers also prefer higher-potency products today than they have in the past.

Here is what we know specifically about how medical marijuana legalization contributed: 

• There is a strong correlation between the medical legalization of cannabis and the potency of illicit cannabis products seized by the Drug Enforcement Administration.
• But research on the topic does not find a causal relationship and concludes that the effect of these laws is on which products are sold rather than the potency of raw cannabis itself.
• Individuals in states that allow medical use of cannabis are more likely to use inherently higher-potency cannabis concentrates.

Read more: Not your grandfather’s weed (July 2024)