When a state legalizes recreational marijuana, the impact is not confined to its own borders. That’s the implication of a new NBER study from the economists Zhuang Hao and Benjamin Cowan, which found that since Colorado and Washington set up legal markets for the drug in 2013, it has been finding its way to neighboring states in greater quantities:
We find that [recreational marijuana legalization] causes a sharp increase in marijuana possession arrests of border counties relative to non-border counties in both the Colorado and Washington regions. If a county shares a physical border with an RML state, it experiences an increase in marijuana possession arrests of roughly 30% following RML implementation (relative to non-border counties in the same region).
The authors note that one common argument for marijuana legalization is fiscal: States may be able to increase revenues by taxing the drug and save money on police and prisons by decriminalizing it. But this paper suggests that some of the cost savings in states with legal marijuana may come at the expense of other states, which have to manage increased drug use, at least in border counties, and which don’t share in the weed tax windfall.
To this concern, drug libertarians might answer, not unfairly: Well, that’s why people should be able to legally buy marijuana in every state. And we might indeed be going in that direction. But for now, most states still have some form of criminal penalty for the sale of marijuana, and the federal ban is still on the books.
Jeff Sessions’ fantasy of a return to 20th-century Drug War policies would almost certainly do more harm than good. But insofar as statewide marijuana legalizations place a significant burden on other states, there is a case for the federal government to err on the side of restriction and use some of the legal means at its disposal to curb the proliferation of cheap pot.