A world with a sudden limit on air travel would be tremendously different from the one we live in now.

The way I think of it, economics and ecology occupy two intellectual silos, isolated from each other. Even when they do take each other into consideration, it's not uncommon for ecologists to spout absolute nonsense about economics, and vice versa.

Compared with U.S. cities, Japanese cities bend over backward to help foreigners. The countryside is another matter.

The Japanese drive on the left side of the road. Most streets literally do not have names.

A world with a sudden limit on air travel would be tremendously different from the one we live in now.

Smartphones can relay patients' data to hospital computers in a continuous stream. Doctors can alter treatment regimens remotely, instead of making patients come in for a visit.

Historically, large-scale global trade has served two functions: 1) the exchange of goods between willing sellers and buyers described in Econ 101 textbooks; 2) as a tool of state aggrandizement, in which the private parties are stand-ins for governmental interests.