Study Links Cannabis Legalization to Rising Workplace Absenteeism

Core Findings Show Measurable Absence Increase

Workers in states with adult-use cannabis laws reported 7-12% more unscheduled absences than employees in prohibition states, according to payroll records analyzed across six years. The study, conducted by researchers at three universities and published in the Journal of Occupational Health Economics, examined longitudinal data from 2.3 million employees in retail, manufacturing, healthcare, and professional services sectors.

The effect size varied by industry. Manufacturing workers showed the steepest increase at 11.8%, while professional services employees registered a 6.9% uptick. Healthcare workers fell in the middle at 9.2%.

Researchers controlled for pre-legalization absence trends, state unemployment rates, seasonal patterns, and demographic variables including age, tenure, and income bracket.

Monday and Friday Absences Spiked Most

Unscheduled Monday absences increased 14% in legal states, while Friday call-outs rose 10%, suggesting weekend consumption patterns may influence weekday attendance. The pattern held across all four industries studied.

Mid-week absences (Tuesday through Thursday) showed a smaller but still statistically significant 5% increase. Researchers noted this distribution mirrors alcohol-related absence patterns documented in earlier workplace studies.

No Clear Link to Workplace Injury Rates

The study found no statistically significant change in workplace injury rates or workers' compensation claims in states post-legalization. This held true even in high-risk manufacturing and construction roles where impairment could theoretically increase accident frequency.

Researchers flagged this as an unexpected result requiring further investigation. One hypothesis: employees may be consuming cannabis off-hours without on-the-job impairment, but experiencing residual effects like fatigue or motivation changes that prompt absences rather than accidents.

Employer Drug Testing Policies Showed Mixed Impact

Companies maintaining pre-employment and random drug testing saw a 3-4% smaller increase in absenteeism compared to employers who relaxed or eliminated cannabis screening post-legalization. But the gap wasn't large enough to fully offset the legalization effect.

Employers who dropped cannabis from their drug panels after state legalization experienced the steepest absence increases, averaging 13.7% above baseline.

The study didn't assess whether testing policies caused the difference or whether companies with stricter policies self-selected for workforces less likely to consume cannabis.

Medical Cannabis States Showed Smaller Effect

States with medical-only programs registered a 3-5% absenteeism increase, roughly half the effect size seen in adult-use jurisdictions. Lower prevalence rates and stricter qualifying conditions in medical programs likely explain the gap.

The data covered 14 medical-only states and 10 states that transitioned from medical to recreational programs during the study window. Absence rates climbed further in states that made the transition. Expanded access appears to drive the effect more than medical necessity.

Economic Cost Estimates Range Widely

Applying Bureau of Labor Statistics wage data, researchers estimated the absenteeism increase costs employers in legal states between $1.8 billion and $4.2 billion annually in lost productivity. The range reflects uncertainty in how to value unscheduled versus scheduled absences and whether employees make up lost hours.

• Low estimate assumes partial productivity recovery through shift coverage and make-up work
• High estimate treats each absence as a full productivity loss with no recovery mechanism
• Mid-range estimate of $2.7 billion assumes 60% productivity recovery

The study didn't account for potential offsetting productivity gains from reduced alcohol consumption or improved employee wellness, variables other research has linked to cannabis access.

Study Limitations and Next Research Questions

The research couldn't determine causation—whether legalization directly caused increased absences or whether unobserved variables correlated with both legalization and absence trends. States legalizing cannabis often differ demographically and culturally from prohibition states in ways the statistical controls may not fully capture.

The study also lacked data on employee cannabis consumption rates, relying instead on state-level policy changes as a proxy. Future research tracking individual consumption and absence patterns would clarify whether the effect concentrates among cannabis users or reflects broader workforce changes.

The data suggest employers in legal states face a measurable attendance challenge, but the mechanism—whether pharmacological, behavioral, or cultural—remains unclear.

For full context on how cannabis legalization is reshaping workplace policies, see the CannIntel topic hub on Cannabis Workplace Policies.

What HR Leaders Should Watch

The findings arrive as more states consider legalization ballot measures in 2026 and 2027. Employers in states on the cusp of legalization may want to benchmark current absence rates and revisit drug-testing policies before laws change.

Study authors recommended employers track absence patterns by day of week and compare pre- and post-legalization trends within their own workforces rather than relying on national averages. Three variables to monitor: Monday call-outs, total unscheduled absence hours, and whether testing policy changes correlate with attendance shifts.