During a Senate hearing yesterday, Tim McAfee, director of the Office on Smoking and Health at the U.S. Centers for Disease Control and Prevention (CDC), described the marketing of electronic cigarettes as "a huge experiment" and argued that "it is not fair to our children to ask them to pay a potential price…for a hypothetical benefit to adult smokers." In fact, he said, "it is egregious to suggest that we need to have kids do this in order for adults to quit."

McAfee was referring to the fear that e-cigarettes will encourage teenagers to smoke, both by getting them hooked on nicotine and by "renormalizing tobacco use" through ads presenting a safer, less irksome, noncombustible alternative. Implicitly recognizing the weak empirical basis for that claim, McAfee said, "We're not saying it is a gateway."

But they are. Last fall McAfee's boss, CDC Director Tom Frieden, claimed "many kids are starting out with e-cigarettes and then going on to smoke conventional cigarettes." Frieden frequently raises the possibility that e-cigarettes will "get another generation of kids more hooked on nicotine and more likely to smoke cigarettes," as he put it in an interview with the Los Angeles Times last month. Yet as Boston University public health professor Michael Siegel notes, "there is no evidence that e-cigarette use leads to cigarette smoking among adolescents."

McAfee, like Frieden, portrays that scientifically unsubstantiated worry as more believable than the "hypothetical benefit to adults smokers." But as Siegel points out, those benefits are in fact quite real, since we know that smoking is much more dangerous than vaping and that many people have switched from the former to the latter. A survey reported last month in the International Journal of Environmental Research and Public Health, for example, collected information from more than 19,000 e-cigarette consumers around the world, 81 percent of whom had completely stopped smoking. The former smokers reported significant improvements in overall health and in specific functions such as breathing, endurance, smell, and taste. The researchers, led by Greek cardiologist Konstantinos Farsalinos, concluded that e-cigarettes "can be effective even in highly dependent smokers," that "side effects are minor," and that "health benefits are substantial."

The sample used in that study was drawn mostly from people who participate in online e-cigarette forums, who may not be representative of vapers in general. You would expect e-cigarette enthusiasts to include a disproportionate number of people who have successfully substituted vaping for smoking. These are nevertheless actual people who have experienced actual benefits, in contrast with the entirely hypothetical group of teenagers who never would have smoked if they had not vaped first, none of whom has been identified so far. Notably, only 0.5 percent of the e-cigarette consumers in Farsalinos et al.'s survey said they were not smokers when they first tried vaping.

Mitch Zeller, director of the Center for Tobacco Products at the Food and Drug Administration (FDA), testified at the same hearing as McAfee, but his comments about e-cigarettes were more temperate and evenhanded. That is encouraging, since the FDA is charged with regulating e-cigarettes, which gives it the power to determine whether they stay on the market and, if so, in what form and on what terms. But Zeller's testimony also highlighted the extent to which the FDA plans to substitute its judgment for that of consumers.

E-cigarettes "have the potential to do good, and they have the potential to do harm," Zeller said. "It really depends on who is using them and how they're being used." For instance, he said, "If we look at a subset of smokers who are otherwise unable or unwilling to quit," and "we could get all of those people to completely switch all of their cigarettes for one of these noncombustible products, that would be good for public health." Then again, he said, some vapers might continue smoking and "start to become less interested in quitting," which "might not be good for public health."

Even that way of framing the issue is too categorical. In Farsalinos et al.'s survey, about a fifth of the respondents did not quit smoking completely, but they did cut back, on average from 20 to four cigarettes today. Like the former smokers, they reported health improvements, although the impact was not as big. Hence dual use could, on balance, reduce tobacco-related disease and death, even if some of those smokers might have quit completely had they never tried vaping.

More fundamentally, the FDA's approach makes sense only if you agree that the government should strive to minimize morbidity and mortality for the population as a whole, as opposed to letting individuals make their own choices. As Zeller explained, "our job as the regulator is to figure out what is going on at the population level." In other words, it's not enough to show that e-cigarettes are safer than the conventional kind, or that individual smokers can dramatically reduce the hazards they face by switching. You also have to show that the resulting reduction in morbidity and mortality is greater than any possible increase in morbidity and mortality among people who start or continue smoking because e-cigarettes are available. "I would absolutely concede that any of these products at an individual level can do good," Zeller said, but "the decisions that we have to make are not going to be made about what might be good for the theoretical individual." And that, in a nutshell, is what's wrong with the collectivist logic of "public health."