There is a built-in incentive for regulators like the Food and Drug Administration to be cautious. Saying no rarely begets significant backlash. Saying yes means owning every negative headline for the next decade or more. So when the FDA does say yes, it’s worth paying attention.

Recently, the agency authorized new e-cigarette products, citing data showing nearly 20% to 35% of adult smokers using the tobacco-flavored pod had stopped smoking cigarettes entirely at six weeks. For the menthol pod, roughly 28% to nearly 50%.