A recent study  links cannabis legalization with lower workers' compensation expense, both in terms of frequency and size of claims, at least among older workers, according to MarketWatch. The study, published by the National Bureau of Economic Research, drew its data from recurring Bureau of Labor Statistics surveys that questioned more than 500,000 people, including asking whether the person received workers’ compensation and, if so, how much.

What the researchers found by looking at these surveys was that states where cannabis is fully legal have 20 percent fewer workers between the ages of 40 and 62 who have received any worker's compensation in the past year, compared to states that have not fully legalized cannabis; what's more, compared to a baseline of about $100, the average payout in those legal states dropped by $21.98.

The study's authors—Rahi Abouk, Keshar M. Ghimire, Johanna Catherine Maclean and David Powell—believe that this decline in workers' comp occurred because once cannabis became legal, people began using it for medicinal purposes, such as chronic pain management, which reduced the need to apply for workers comp. In contrast, a 2018 study found that those taking opioid painkillers were on workers' comp for longer periods of time than the average.