If you can't build 'em, grow 'em

Bill Easterly reminds a classic anecdote (due to David Friedman) illustrating the point that, looking at their effects on the economy, trade and technological progress are the same thing:

There are two technologies for producing automobiles in America. One is to manufacture them in Detroit, and the other is to grow them in Iowa.

How does one manufacture cars in Detroit? I don't know; ask an engineer or whoever it is that knows about stuff like that. How does one grow cars in Iowa? Like this:

First you plant seeds, which are the raw material from which automobiles are constructed. You wait a few months until wheat appears. Then you harvest the wheat, load it onto ships, and sail the ships eastward into the Pacific Ocean. After a few months, the ships reappear with Toyotas on them.