Teenage vaping, don’t do it. Photo: Gabby Jones/Bloomberg via Getty Images

I think the backlash against Juul, most recently taking the form of a vote by the San Francisco Board of Supervisors to ban retail sales of nicotine vape products, is best understood in the context of the extreme success of public-health campaigns against teen smoking.

Teenagers essentially do not smoke cigarettes anymore. The National Adolescent Drug Trends survey from the University of Michigan found in 2018 that under eight percent of 12th graders reported smoking at least one cigarette in the last 30 days, and less than four percent reported they had smoked cigarettes daily for the last month. Those figures are way down from peaks of 36 percent and 25 percent, respectively, in 1997.

So, a parent who knows (or fears) that his or her child is Juuling is unlikely to say, “Well, at least he’s not smoking.” Vapes are being widely used by adolescents who otherwise wouldn’t be using nicotine at all — vaping has become nearly as popular as smoking cigarettes once was — and it makes sense that parents want the government to do something about it.

On the other hand, there is reason to worry that if we crack down on vaping now, that will lead some people to smoke cigarettes who otherwise would not have. And it is a consensus among public-health experts that nicotine vapes are less dangerous than cigarettes, though not about precisely how much less dangerous. So, reasonable people might disagree about how to analyze the public-health tradeoff that comes from, on one hand, some adults switching from cigarettes to safer vapes, and on the other hand, some adolescents take up vaping even though they otherwise would never have used nicotine at all.

Ideally, you should want a public policy that encourages smokers to switch to vaping; that discourages nonusers of nicotine products, especially minors, from taking up any nicotine product; and that discourages vape users from switching to combustible cigarettes. San Francisco’s proposed policy (a second vote by the Board of Supervisors is required before it becomes law) fails to meet the third test because it makes traditional cigarettes easier to obtain than vapes. Adult smokers who are thinking about switching to vaping, or who have already done so, might continue buying cigarettes because the city will make that the more convenient option. And adolescents in San Francisco who currently use Juul but can’t get it anymore might start smoking easier-to-find cigarettes.

As I have written before, the way to ensure that new rules about vaping don’t lead to more cigarette smoking is to impose further restrictions on the sale of cigarettes, up to and including outright bans. Cigarettes should be harder to buy than vapes, and harder to buy than they currently are.

The justification for keeping cigarettes legal has gotten much weaker with the rise of vaping. We have traditionally allowed cigarettes because we value freedom and think adults should be able to use nicotine if they want, and because we think bans are likely to be ineffective and create harmful and dangerous black markets. Now, vapes offer adults a less dangerous way to use nicotine, and broad consumer acceptance of the vape alternative means cigarette bans are likely to be more effective than they once were. The liberty justification for allowing cigarettes is not gone (some consumers have a genuine preference for cigarettes over vapes) but it is weaker than it was, and it weighs against the major health benefits of getting people to stop smoking.

So, if San Francisco officials really wanted to be at the vanguard of public health around nicotine, they should have started with a ban on the sale of cigarettes.

A cigarette ban would still have left them with the very real issue of how to address teen vaping. And an overall nicotine-free policy — no Juul sales, no cigarette sales — might not be so bad from this perspective: Teens and adults who want nicotine would have to look to sources outside San Francisco whether they wanted cigarettes or Juul, so there would be less reason to worry it would shift anyone to cigarettes.

But the city has options available besides an outright Juul ban. It could look to two other products that are sold on an age-restricted basis in California: alcohol and marijuana. Retailers of these products face significantly more stringent requirements around licensing and age verification than tobacco retailers do. And since it won’t be viable for every jurisdiction to ban all nicotine products — if Juul is the pressure valve that makes a cigarette ban possible, you’ll have to be able to get Juul somewhere — someone is going to have to pilot an effective age-restriction regime. It could have been San Francisco.