In the heat of political debate, there's a tendency for supporters of cannabis legalization to deny that anything could go wrong. But even if many of the harms are either entirely imaginary or grossly exaggerated, plenty are real and important. As we move toward legalization, we should be alert to the problem of minimizing the risks.
For instance, it's foolish to deny that legalization will likely increase the number of teenagers who start using heavily and add to the pool of adults who have problems controlling their marijuana use. The RAND Corporation estimates that legalization—without extremely high taxes—could drop pre-tax cannabis prices to below 20 percent of current levels, and younger users—especially heavy smokers—are especially sensitive to prices. The number of marijuana users hasn't changed much over the past two decades, but the number of heavy consumers has soared up sevenfold from its low point in 1992.
Supporters and opponents of cannabis legalization agree on the importance of preventing an increase in underage use. The Department of Justice has asserted "preventing distribution to minors" as one of eight guidelines that states should follow in order to avoid federal intervention. But there's no reason to think that the policies proposed for keeping cannabis out of the hands of minors once it's legal for adults are up to the task.
Authorities in Washington and Colorado appear determined to make it much more difficult for minors to buy store cannabis than it currently is for them to buy tobacco or alcohol. Historically, the laws against selling alcohol and tobacco to minors have been enforced only sporadically, and it turns out that enforcing them more aggressively—for example, by sending undercover youth buyers into stores to attempt purchase without identification—can succeed in reducing underage drinking and its attendant harms. Both Colorado and Washington propose to apply that model to cannabis with special force, with more frequent inspections and stiffer penalties.
But just enforcing the law against direct sales to minors can't meet the promises that governments have made to voters. When minors can't buy alcohol from stores, they "borrow" from their parents' supplies, find older friends or relatives willing to buy for them, or look for the drunk outside the liquor store willing to buy a case in return for keeping a couple of beers for himself. Store purchase accounts for only 10 percent of drinks consumed by minors; with tobacco, a bit more than half (53 percent) of past-month underage smokers bought from a store in that period. Why should we expect cannabis to be different?
Indeed, it could well be worse. A pack of cigarettes is worth $5 to $10 in most places and weighs about an ounce; an ounce of cannabis—the legal purchase limit in Colorado and Washington—is worth 50 times as much and supplies even a heavy user for a week or more, while for a regular smoker a pack of cigarettes lasts less than a day. There are about a million daily marijuana users between 21 and 25 with annual incomes below $20,000. How many of them would turn to cannabis reselling—buying from a licensed store and then selling it to the underage—to help pay for their own use?
Of course, there are ways to control diversion, but they're difficult and costly. Informal cannabis transactions are harder to detect because they're usually executed discreetly: 80 percent indoors, and a similar percentage among friends or family. How comfortable should we be handing out severe punishments for supplying marijuana to underage users when the suppliers are themselves teenagers?
During the transition from illegal to legal marijuana markets, strictly illegal growers and sellers will be available as a back-up source of supply for underage users if leakage from the legal market is stopped. About a quarter of the $40 billion annual cannabis market involves sales to minors; that's a big chunk of revenue to leave in strictly illegal hands after legalization.
Given that minors will have access one way or another, it's probably safer that they get tested and labeled material from low-level and poorly-organized lawbreakers—the 22-year-old looming outside the dispensary, or maybe their friend's older brother—than to have them continue to be supplied by illegal growing organizations.
Overall, then, while we should try to erect barriers against underage purchase, we should also expect those barriers to leak.
So the key to preventing an upsurge in youth access with marijuana legalization is the same as the key to preventing an upsurge in substance use disorder among adults: keep the prices high. With production costs likely to plummet, that will require either very high taxes—based on THC content rather than on purchase price, as in Colorado or Washington, or on the weight of the plant material, as recently passed in Oregon—or tight production quotas.
You didn't really think this was going to be easy, did you?
Mark Kleiman is Professor of Public Policy at the UCLA Luskin School of Public Affairs. Steven Davenport is a graduate student at the Heinz School of Public Policy and Management at Carnegie Mellon University. Through BOTEC Analysis Corporation, they provided advice to the Washington State Liquor Control Board on the implementation of Washington's legal cannabis market.