Medical Marijuana has caused a 15% drop in alcohol sales. Considering that medical users are just a handful of the population that can legally access cannabis, recreational use is likely to lead to an even greater drop in alcohol consumption in the future.
“We find that marijuana and alcohol are strong substitutes” for each other, the study concluded. “Counties located in [medical marijuana] states reduced monthly alcohol sales by 15 percent” after the introduction of medical marijuana laws.
But this doesn’t mean that weed is just as bad as booze, or that this is a bad thing at all. Just the reverse, as many studies support that cannabis has several health benefits, and is much safer than alcohol.
This study is yet one more in a growing body of evidence showing that marijuana can reduce alcohol use. As alcohol is more harmful, to both individuals and society, this represents a notable public health benefit.
Marijuana has no known fatal dose, unlike alcohol — people don't die of marijuana poisoning, but excessive alcohol use kills nearly 90,000 people in the United States each year. Alcohol is more addictive, far more likely to cause vehicle accidents, and much more closely linked to violent and aggressive behaviour than marijuana is.
If the findings of the study are correct, it's likely that the effect of full marijuana legalization on alcohol use is understated.
Researchers used data on alcohol sales from Nielsen's Retail Scanner database, which includes product-level sales data from 90 retail chains across the United States--an improvement over other ways of measuring alcohol consumption — survey respondents, for instance, often drastically understate their alcohol consumption when asked about it.
The researchers then compared alcohol sales between states that have implemented medical marijuana laws and those that have not, before and after the change in marijuana laws. They also corrected for economic and demographic variables known to affect alcohol use, such as age, race and income.
While a solid body of evidence points to the availability of marijuana decreasing use of alcohol, not all of the existing research fully supports that conclusion. An analysis of 39 reports found that 16 supported marijuana substitution for alcohol, though 10 suggested that it increased alcohol use. The other 12 studies did not support either conclusion.