Hmm. I wouldn’t quite go as far as stupid. The argument is that humans, in the aggregate, don’t choose trips exclusively based on passenger miles; they (often,

Hmm. I wouldn’t quite go as far as stupid. The argument is that humans, in the aggregate, don’t choose trips exclusively based on passenger miles; they (often, though not always) think about how many hours they’re willing to devote to travel. If cheap air travel availability as a mode induces people to travel 10x more passenger miles, in a world where airlines were only as safe per passenger mile as cars, there would be a net reduction in public health. But we don’t live in that world; planes are better in safety when measuring by passenger hour than cars, so in fact we’ve improved public health.