Youth smoking is down, but thanks to what?

We received some welcome news this week from the Food and Drug Administration: Cigarette smoking by high school students has been cut in half since 2011, from 15.8 percent to 8 percent — a remarkable and previously unanticipated public health victory.

Unfortunately, it appears federal authorities may be misattributing the cause. In his announcement about the news, FDA Commissioner Scott Gottlieb attributes most, if not all, of this reduction in smoking to "The Real Cost" campaign, a federally-sponsored program that has only been in place since 2014. That's notable, among other reasons, because teen smoking had already fallen to a rate of 9.5 percent by 2014.

Despite substantial evidence in federally-sponsored surveys in the U.S. and abroad showing that remarkable reductions in teen and adult smoking have been concurrent with the increasing popularity of e-cigarettes, the FDA announcement makes no reference to the possibility that much, if not most, of the recent reductions in teen smoking may be attributable to the availability of e-cigarettes.

In fact, Gottlieb urges continuing efforts to reduce teen use of all nonpharmaceutical nicotine delivery products, while endorsing expanded efforts at smoking cessation that rely on the pharmaceutical nicotine gums, patches, and other products that have proved to be of only marginal effectiveness over the past four decades.

These efforts are driven by unfounded fears that use of e-cigarettes will lead teens to progress to traditional cigarette smoking. But even with a growing number of U.S. and British data sets on the topic, there is not a single reported case of a nonsmoker who initiated consistent nicotine use with e-cigarettes and then transitioned to consistent use of tobacco cigarettes.

This public health victory is too important to leave to chance and guesswork.

If Gottlieb has evidence to support the claim that The Real Cost campaign "has already helped prevent nearly 350,000 kids from smoking cigarettes since it launched in 2014," he should present it to the public. Regulators and public health authorities also should present and discuss the evidence for and against the possibility that the availability of e-cigarettes and related vapor products may, in fact, have played a major role in securing these reductions in smoking.

This is important, because recently promulgated regulations from the FDA threaten to eliminate more than 99 percent of e-cig products from the marketplace before the end of 2018, including all or almost all of the vape-shop component of this industry. The limited data available strongly suggest that the vape-shop products — with their ability to customize devices, flavors and strengths of nicotine to satisfy the preferences of each smoker, and modify the flavors and strength of nicotine over time to prevent relapse to cigarettes — may be more effective than the mass-market products in achieving and maintaining reductions in smoking in both youth and adults.

This week's news marks a tremendous step toward reducing the 480,000 deaths we continue to see each year from smoking-related illness and disease. But it is essential to remember that substantially all of those deaths are due to a single product — the combustible cigarette. Deaths from all other tobacco products are so few and so hard to discern from background noise that they aren't even included in the statistics.

There is one outcome the FDA should feel comfortable predicting: If e-cigarettes are wiped off the market in the United States, nicotine consumers left with nowhere to turn to satisfy their cravings will return to smoking much more harmful, and more deadly, combustible cigarettes.

Joel Nitzkin is a contributor to the Washington Examiner's Beltway Confidential blog. He is a senior fellow for tobacco policy with the R Street Institute.