Does Marijuana Legalization Lead to Fewer Traffic Fatalities?

Photo: aforero

That’s the claim of a new paper by D. Mark Anderson and Daniel I. Rees, put out by the IZA, titled “Medical Marijuana Laws, Traffic Fatalities, and Alcohol Consumption”:

To date, 16 states have passed medical marijuana laws, yet very little is known about their effects. Using state-level data, we examine the relationship between medical marijuana laws and a variety of outcomes. Legalization of medical marijuana is associated with increased use of marijuana among adults, but not among minors. In addition, legalization is associated with a nearly 9 percent decrease in traffic fatalities, most likely to due to its impact on alcohol consumption. Our estimates provide strong evidence that marijuana and alcohol are substitutes.

 As Rees told the East Bay Express:

“If critics want to collect the data themselves, boy, the results will jump out at them the way they jumped out at us. … Our results are pretty robust. We’re pretty confident they’re going to hold up … Include us in that group who thought, ‘This is going to be crash central. … We were totally surprised when the results came out so strong in the other direction.”

Not surprisingly, the paper has already been highlighted on the NORML blog.

If you haven’t already dumped your BUD stock, is it time to do so now?

Finally, we’ve run two Freakonomics Quorums in the past on the topic of decriminalizing marijuana. Part 1 is here; Part 2 is here.


If they substitute, then shouldn't we also see decreased crimes related to alcohol - like fights - and more related to pot, whatever those are?


These crimes could be also related to the use of Marijuana.


Not really. In my experience, at least, marijuana tends to counter any aggressive tendencies, while alcohol aggravates them in at least a fraction of the drinking population.

Todd Hadden

"legalization is associated with a nearly 9 percent decrease in traffic fatalities"
Does this mean that Tax Rev from Alcohol is falling too? How much does this cost the states
that have legalized medical marijuana?


And how much tax revenue would the nation bring in (both as a whole and by state) bring in were it federally decriminalized? That would certainly offset a very large portion of any possible drop in alcohol tax revenues.


AB is the ticker for Alliance Bernstein, not Anheuser-Busch, which trades as BUD.

Stephen J. Dubner

Oops. Thnx, SJD


Greetings from the Netherlands, I'll light one (or two) up for all of you tonight.

How is Medical Marijuana a substitute for alcohol? Don't you need a prescription?

Btw Todd Hadden, they've thought about that over here and are now proposing to further legalize and then tax marijuana

Enter your name...

No, you can't actually get a "prescription". You need a "recommendation", which California can usually be bought for cheap under the flimsiest of pretexts from physicians. The medical marijuana stores usually have a list of sympathetic physicians available. The one nearest me apparently arranged for one to make on-site visits to give a written recommendation to anyone willing to show up during "office hours" and pay her fee. Various investigations have shown that these sympathetic people offer recommendations to almost 100% of requesters, even when given transparent excuses like "My foot kind of hurts sometimes".

The users' demographics should give you an idea of how "medical" this is: In California, more three-quarters of the users are male, and half of them are in their 20s. That sure sounds like a program that targets patients with serious chronic diseases like AIDS (median age: 45) and cancer (median age: 73), right?


Chris Purnell

Is this a nail in the coffin of a legal class 'A' drug?


So it seems we may be adding traffic deaths in non-trivial numbers to the legacy of the drug war. It's the gift that keeps on giving.

Jer Smith

Because I don't like to dig through several links to find the link to the study itself:


Crimes related to pot... You guys have obviously never tried marijuana.