Should Thinner People Fly Cheaper?

A story on Yahoo news mentions that the Philadelphia newspapers are running advertisements for a fake airline, Derrie-Air (get it?). The airline advertises that it is carbon-neutral, and that it charges per passenger pound — $1.40 from Philadelphia to Chicago, $2.25 from Philadelphia to Los Angeles.

While quite mythical, this pricing structure is not unreasonable: the heavier people cost more to ship; and at a time when fuel prices are so high, this seems especially important and a good way of letting price reflect marginal cost.

Also, heavier people spill over onto their neighbors’ seats, generating negative externalities for the other passengers. So I hope a few real-world airlines take notes and think about charging heavier passengers extra.