Cannabis News for Florda
By Wolfgang H. Vogel, PhD Recreational Marijuana Legislation (RML) has raised many concerns about its positive or negative consequences. In a previous report, the... Brief Review of the Effects of Recreational Marijuana Legislation on Academic Student Performance, Crime and Driving Accidents

By Wolfgang H. Vogel, PhD

Recreational Marijuana Legislation (RML) has raised many concerns about its positive or negative consequences. In a previous report, the author reviewed the effects of RML on the use and abuse of marijuana and other substances (Cannabis Law Report). The available evidence showed that the effects of RML were minimal if they existed at all. In a paper to be published in the Journal of Drug Abuse, the author now examined the effects of RML on students’ academic performance, crime and traffic accidents.

First, did RML affect the academic performance of pupils and students?

There are few studies and data available on this topic. Nevertheless, data from Colorado (legal since 2012) showed that school suspensions spiked between 2013 and 2014 but then declined significantly later on. After RML, expulsions decreased by 25 percent. The four-year graduation rate rose steadily while the dropout rate fell. SAT scores increased from 944 in 2016 to 1001 in 2019. In Oregon (legal 2015) the graduation rate rose steadily after RML. A comparison of 4 states with and without RML showed that the percentages of 8Th grade math proficiency, 8th grade reading proficiency, graduation and high AP scores did not differ significantly among these states. Similar results were obtained when examining the performance of college students. The undergraduate graduation rate in Washington (legal since 2012) in 2019 was about 38% for the first 4 years which is about the national average. Similarly, graduation rates in Oregon rose over the last years and were 76% in 2017 and 79% in 2018. The University of Colorado at Boulder reported that average cumulative GPA scores are slowly rising from 3.04 in 2010 to 3.15 in 2019. In conclusion, available evidence does not show a deleterious effect of RML on the academic performance of pupils or student. 

Second, did RML increase crimes in general?

Available evidence is somewhat controversial. A 2015 report by the Rocky Mountain High Intensity Drug Trafficking Area Program Property showed that in Denver violent crime increased 6.7 %, all crimes increased 6.2 %, crimes against persons increased 7.5 percent and crimes against property increased 6 % after RML However, the report finished by saying “This is not to infer that the data is due to the legalization of recreational marijuana”. A report in 2021 showed a crime-exacerbating effect as reflected by substantial increases in the rates of multiple types of serious crimes in Oregon following RML relative to non-legalized states. These included property and violent crimes overall, as well as other crimes such as burglary, motor vehicle theft, larceny and aggravated assault. In contrast, researchers from the universities in Washington and Utah compared monthly crime rates in Colorado and Washington to crime rates in 21 states that have not legalized the recreational use of marijuana. Crime rates came from the FBI’s Uniform Crime Report in the years 1999 to 2016. The study found no statistically significant long-term effects of recreational cannabis laws on the initiation in violent crimes, auto theft or property crime rates in either Colorado or Washington, with the exception of a decline in burglary rates in Washington. A second report found that the violent crime rate had declined, and the overall crime rate had remained at a 40-year level in the State of Washington after RML except violent crime which had actually declined by 10% between 2011 and 2014 including a 13% decrease in the murder rate. A study combining county-level difference-in-differences found that RML caused a significant reduction in rapes and property crimes in Washington. A 2018 study using a complicated quasi-experimental, multi-group interrupted time-series design to determine crime rates in Colorado and Washington concluded that RML and marijuana sales had a minimal to no effect on major crimes in these states. A survey, interestingly coming from a University in Italy, found that legalization of recreational marijuana in Oregon and Washington did not increase overall crime rates but reduced rapes and thefts. In conclusion, it can be safely concluded that RML did not cause a significant increase in crime but actually might have shown no effect or a reduction. 

Third, did RML increase the number of traffic accidents and fatalities?

This question is more difficult to answer because existing studies are quite controversial. A summary report of the Governors Highway Safety Association concluded that fatal crashes involving marijuana increased in both Colorado and Washington after RML. Marijuana-related traffic deaths increased 66% in the four-year average after RML as compared to the four-year average prior to legalization. During the same time period, all traffic deaths increased 16%. Analysts from the Insurance Institute for Highway Safety and the Highway Loss Data Institute (HLDI) found that the frequency of collision claims per insured vehicle/year rose a combined 6 % following the start of retail sales of recreational marijuana in Colorado, Nevada, Oregon and Washington, compared with the control states of Idaho, Montana, Utah and Wyoming. A separate HLDI study examined police-reported crashes before and after retail sales began in Colorado, Oregon and Washington and found that the three states combined saw a 5.2 percent increase in the rate of crashes per million vehicle registrations compared with neighboring states that didn’t legalize marijuana sales. In contrast, a paper in 2019 compared Colorado, Washington and Oregon (all with RML) with nine neighboring jurisdictions without RML. There was a pooled step increase of 1.08 traffic fatalities per million residents followed by a trend reduction of −0.06 per month. However, these effects were similar in both RML and non-RML states. A 2017 study found that three years after recreational marijuana legalization, changes in motor vehicle crash fatality rates for Washington and Colorado were statistically not different from those states without RML The Colorado Departments of Public health and Safety released the following fatal accident figures of 359, 335, 388 and 335 from years 2014 to 2017.These data suggest that fatal accidents did not change significantly during the 4-year period following RML. In conclusion, it can perhaps be posited if there would have been a marked effect of RML on traffic accidents, studies would have been more consistent. Thus, it can be safely stated that RML might have a mild effect on traffic accidents and deaths if it had an effect at all.


This review dispels general concerns about the deleterious effects of RML on the academic performance of pupils and students, crime and traffic accidents in that RML did not cause any significant detrimental effects if it caused any effects at all.

Wolfgang H. Vogel, Ph.D., is Professor Emeritus of Pharmacology and former Professor of Psychiatry and Human Behavior and may be reached at

No comments so far.

Be first to leave comment below.

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.