States with adult-use marijuana legalization see fewer and less expensive workers’ compensation claims, according to a new study.

The research, published in the National Bureau of Economic Research, reveals the number of worker compensation claims for adults aged between 40 and 62 dropped 20 percent where cannabis was legalized compared to prohibition states. The average value of successful workers’ compensation claims also fell by 20.5 percent following recreational marijuana legalization.

“We find that WC [workers’ compensation] receipt declines in response to RML [recreational marijuana law] adoption, both in terms of the propensity to receive benefits and benefit amount,” the study’s authors write.

The team behind the study, hailing from the University of Cincinnati, Temple University, RAND Corporation and Wayne University, hypothesized that access to legal cannabis may allow workers to better manage their health conditions, which might then reduce the need for compensation claims by injured or ill workers.

To determine whether or not this is the case, the researchers analyzed survey data collected annually from 2010 to 2018 comprising interviews with 150,000 US residents, but focused on the responses of those aged 40 to 62. Commenting on the decline in the number of workers’ compensation claims and in the amounts paid out for successful claims, the authors said this could not be due to changes in labor supply or industry composition following marijuana legalization.

“These results are not driven by pre-existing trends. … The observed reduction in WC benefits [was] not due to a concurrent decrease in labor supply mechanically reducing WC participation or due to industry composition shifts which lead to a higher share of the workforce in safer industries,” the authors write. “Instead, we observe an increase in labor supply due to RML adoption, which is further in line with RMLs improving work capacity among older adults.”

The researchers go on to note that their research suggests recreational cannabis legalization could yield improvements in work capacity, contrary to common assumptions that smoking marijuana outside of work hours has a negative impact on productivity.

“The present study provides empirical evidence on the consequences of marijuana legalization on issues related to the labor market outcomes, in particular, WC claiming of older adults. … Our findings suggest potentially important benefits to older workers and society at large. Broadly, we show non-trivial improvements in work capacity, which we proxy with WC benefit receipt and various other metrics in our mechanism analysis, among older adults.”

Maine is the only state to legalize adult-use marijuana that prohibited employers, schools and landlords from discriminating against staff or applicants on the basis of off-work cannabis use.

The new study builds on the findings of a similar study from last year by the same researchers. It revealed that workers’ compensation claims declined by 6.7 percent in states that implemented a medical marijuana program.

“On net, the available findings suggest that MML passage may increase work capacity among older adults, reduce work absences, improve workplace safety, and reduce WC claiming and the pain and suffering associated with workplace injuries,” the researchers wrote in the conclusion of their 2020 study.