Students with access to legal marijuana don’t do quite so well compared to students that do have access, according to new economic research. You might put that finding that in the “not entirely surprising” pile.
The two economists at Maastricht University who wrote the paper found they had a natural case study on their own doorstep.
Though the Netherlands has legalised cannabis through a series of regulated coffee shops, the city of Maastricht decided to crack down on “drug tourism,” and in 2011 everyone who wasn’t from the Netherlands, Germany and Belgium (which border the town) were banned from using the shops in the city.
The authors also had access to 54,000 course grades from the university, broken down by nationality. Most of the students (92%) getting those grades were German, Dutch and Belgian citizens, who were allowed to use the shops. The rest weren’t allowed to.
On the chart below you can see what happened. The dashed blue line is the grades of the Dutch, Belgian and German students (whose average course grade is on the left-hand axis), and the red is for all other nationalities. The two red vertical lines denote the period that the nationality ban lasted for Take a look at the gap that opened up:
Students from the other nationalities (whose grades are on the right-hand axis) still did worse than the Dutch, German and Belgian students — but they narrowed the gap significantly.
We find that the performance of students who lose legal access to cannabis improves substantially. Our analysis of underlying channels suggests that the effects are specifically driven by an improvement in numerical skills, which existing literature has found to be particularly impaired by cannabis consumption. This provides perhaps the first clear causal evidence of an important positive effect on short term productivity of restricting legal access to cannabis. Our findings also imply that individuals do change their consumption behaviour when the legal status of a drug changes.
The most clearly-effected were students studying mathematics-related courses, according to authors:
The estimates reveal that the policy effect is more than five times larger for numerical than for non-numerical courses…
We can confirm that numerical courses are on average more difficult: only two-thirds of students pass these compared to the almost 80 per cent that pass non-numerical courses. Despite these baseline differences in passing rates in the different course types, the difference in the estimated policy effect remains very large, with the probability of passing being three times larger for maths oriented courses than non-mathematical ones. This difference is statistically significant and a strong indicator that the improvement in performance we observe is driven by Non-DGB students altering their cannabis consumption as a result of the change in access policy.
Overall, the study says that the restriction period saw a 5.4% rise in the likelihood of the students banned from coffee shops to pass their course. They say “our findings have potentially important policy implications for countries which are considering the relaxation of drug laws,” so don’t be surprised if you hear these statistics cropping up when European countries and US states are considering relaxing their drug prohibition laws.
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