Access to medical marijuana tied to reduced workers' comp claims

Legalizing access to medical marijuana may lead to fewer workers’ compensation claims, a U.S. study suggests.

In states with laws allowing medical marijuana, researchers tied the accessibility of cannabis to a nearly 7% decline in workers’ comp claims. When there were claims, they were for shorter periods of time, on average, after medical marijuana was legalized, according to the analysis in Health Economics.

“We think there is a lot of overlap between conditions for which medical marijuana can be used in managing symptoms and the types of illnesses that lead people to file workers’ compensation claims,” said study coauthor, Catherine Maclean, an associate professor in the economics department at Temple University in Philadelphia.

For instance, medical marijuana can be used to reduce chronic pain symptoms. While cannabis use isn’t going to cure the condition causing the pain, it can allow the individual to mitigate the symptoms, said Maclean, who is also a research associate at the National Bureau of Economic Research and a research affiliate at the Institute for Labor Economics.

“When a state adopts medical marijuana legalization there is a modest decline in the propensity to file claims and a reduction in the (overall average) income people receive from workers’ compensation,” Maclean said.

In some of her earlier research, Maclean found that after legalization of medical marijuana, older workers experienced a reduction in pain and an increase in the number of hours worked.

To look at the potential impact of medical marijuana legalization on workers’ comp claims, Maclean and her coauthor turned to data from the Census Bureau’s Annual Social and Economic Supplement to the Current Population Survey in 1990-2013. Each year between February and April, the survey interviews 150,000 U.S. residents aged 15 and older.

When the data were analyzed, the researchers found a 6.7% decrease in claims when medical marijuana was legally available. In addition, the dollar amount of claims decreased by 0.8%.

The new study provides a window on the possible impact of medical marijuana legalization on people’s ability to work even when in pain, said David Powell, a senior economist at the RAND Corporation in Arlington, Virginia.

“The literature studying medical marijuana laws is constantly trying to understand whether these policies provide additional opportunities for pain management,” Powell said in an email. “This study takes a very clever look at whether medical marijuana policy affects workers’ compensation claiming behavior, an interesting proxy for the ability to work with reduced pain that this literature has not studied before.” Overall, the study is very carefully done and provides convincing evidence, he said. “The estimates are relatively small in terms of workers’ compensation claiming behavior but possibly hint at bigger effects on other labor-supply margins.”