Marijuana Legalization and Impact on the Workplace


Off-the-job cannabis use is not positively associated with elevated rates of occupational accidents or injuries

  • “Canadian workers participating in a yearly longitudinal study (from 2018 to 2020) with at least two adjacent years of survey data comprised the analytic sample (n = 2745). The exposure was past-year workplace cannabis use (no past-year use, non-workplace use, workplace use). The outcome was past-year workplace injury (yes/no). … Compared to no past-year cannabis use, there was no difference in workplace injury risk for non-workplace cannabis use.”
  • “We performed a cross-sectional analysis of the Canadian Community Health Survey (2013-16) of working individuals. We used multiple logistic regression modelling to calculate the odds of experiencing a work-related injury (defined as non-repetitive strain injury) among workers who reported using cannabis more than once during the prior 12 months as compared to non-users. … We found no association between past-year cannabis use and work-related injury. The association was unchanged in the subgroup analysis limited to high injury risk occupational groups.”
  • “Although it is common for organizations to screen employees and applicants for substances including cannabis and for politicians and societal leaders to make sweeping claims about cannabis, there is virtually no empirical research exploring cannabis use in relation to the modern workplace. … To address this gap in organizational and societal knowledge, we proposed a temporal-based cannabis framework that predicts relationships between three different forms of cannabis use (before, during, and after work) and five forms of workplace performance. … [C]ontrary to commonly held assumptions, not all forms of cannabis use harmed performance. In fact, after-work cannabis use did not relate to any of the workplace performance dimensions. This finding casts doubt on some stereotypes of cannabis users and suggests a need for further methodological and theoretical development in the field of substance use.”
  • “This systematic review investigates the potential link between cannabis use and occupational injury. Consequently, it appraises all available current literature from five databases. … The current body of evidence does not provide sufficient evidence to support the position that cannabis users are at increased risk of occupational injury.”
  • “Legalizing medical marijuana was associated with a 19.5% reduction in the expected number of workplace fatalities among workers aged 25-44. … The association between legalizing medical marijuana and workplace fatalities among workers aged 25-44 grew stronger over time. Five years after coming into effect, MMLs were associated with a 33.7% reduction in the expected number of workplace fatalities. MMLs that listed pain as a qualifying condition or allowed collective cultivation were associated with larger reductions in fatalities among workers aged 25-44 than those that did not. … The results provide evidence that legalizing medical marijuana improved workplace safety for workers aged 25-44.”
  • “There is no or insufficient evidence to support … a statistical association between cannabis use and … occupational accidents or injuries.”
  • “Many factors contribute to occupational injuries. However, these factors have been compartmentalized and isolated in most studies. [This study] examined the relationship between work-related injuries and multiple occupational and non-occupational factors among construction workers in the USA.… [Among non-occupational factors associated with workplace accidents, being] obese/overweight, smoking, and cocaine use were risk factors for work-related injuries; however, drinking and marijuana use were not significant [factors].
  • Employees who test positive for marijuana in workplace drug tests are no more likely to be involved in occupational accidents as compared to those who test negative. “This study fell short of finding an association between marijuana use and involvement of workplace accidents. … This study cannot be taken as definitive evidence of absence of an association between marijuana and work related accidents but the findings are compelling.”
  • “[I]t is not clear that heavy cannabis users represent a meaningful job safety risk unless using before work or on the job; urine tests have poor validity and low sensitivity to detect employees who represent a safety risk; … [and] urinalysis has not been shown to have a meaningful impact on job injury/accident rates.”

Liberalized marijuana laws are associated greater labor participation, lower rates of absenteeism, declines in workers’ compensation filings, and higher wages

  • “Despite dramatic increases in support for recreational marijuana legalization, research has only recently begun to explore the broader socioeconomic impacts of increases in access. This study is the first to explore the impacts of the adoption of RMLs on adults’ wages and labor market outcomes. … [W]e find little support for the hypothesis that RML adoption affects employment and wages among working-age individuals. For some demographic sub-groups, we find evidence of modest increases in employment or wages, particularly for individuals over age 30 (in the shorter-run), younger racial/ethnic minorities, and those working in the agriculture sector. These results are consistent with the opening of a new licit industry for marijuana and (especially for older individuals) a substitution away from harder substances such as opioids.”
  • “We evaluate the effect of RMLs [recreational marijuana laws] on WC [workers’ compensation] benefit receipt and WC income over the period 2010 to 2018 using the Annual Social and Economic Supplement (ASEC) of the Current Population Survey (CPS). … Our results show a decline in WC benefit propensity of 0.18 percentage points (‘ppts’), which corresponds to a 20.0% reduction in any WC income, after states legalize marijuana for recreational use. Similarly, we find that annual income received from WC declines by $21.98 (or 20.5%) post-RML. These results are not driven by pre-existing trends. … 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.”
  • “We study the effect of state medical marijuana laws (MMLs) on workers’ compensation (WC) claiming among adults. … We use data on claiming drawn from the Annual Social and Economic supplement to the Current Population Survey over the period 1989 to 2012, coupled with a differences‐in‐differences design to provide the first evidence on this relationship. Our estimates show that, post MML, WC claiming declines, both the propensity to claim and the level of income from WC. These findings suggest that medical marijuana can allow workers to better manage symptoms associated with workplace injuries and illnesses and, in turn, reduce need for WC.”
  • “Utilizing the Current Population Survey, the study identifies that absences due to sickness decline following the legalization of medical marijuana. … The results of this paper therefore suggest that medical marijuana legalization would decrease costs for employers as it has reduced self-reported absence from work due to illness/medical issues.”
  • The enactment of medical marijuana laws is associated with a “9.4 percent increase in the probability of employment and a 4.6 percent to 4.9 percent increase in hours worked per week” among those over the age of 50. “Medical marijuana law implementation leads to increases in labor supply among older adult men and women.”
  • Marijuana decriminalization is associated with increased probability of employment, particularly for young males, and an average increase of 4.5 percent in weekly earnings. African American males experienced the greatest average wage increase. “This data provides suggestive evidence that marijuana decriminalization laws improve extrinsic labor market outcomes. … This result is consistent with existing literature that suggests black adults, especially men, stand to benefit the most from removing these penalties.”