Here’s a letter to Slate:
I enjoyed Timothy Noah’s review of my colleague Tyler Cowen’s book The Great Stagnation  (“Don’t Worry, Be unhappy ,” Feb. 21). But Mr. Noah oversimplifies Cowen’s thesis by suggesting that Cowen measures an innovation’s merit by how much employment it creates.
It’s true that Cowen notes that (as Mr. Noah reports with dismay) “the iPod has created fewer than 14,000 jobs in the U.S.” But immediately after noting this fact, Cowen rightly observes that “we should applaud the iPod for creating so much value with so little human labor” [original emphasis].
Mr. Noah is wrong to suppose that the value of innovations is found in the number of workers they employ. Consider agriculture: the many innovations in that arena over the years – such as mechanized harvesters, chemical fertilizers, and bio-engineering to increase crop yields – have dramatically reduced the number of people employed in agriculture. Would we be remotely as wealthy as we are today if it still took nine of us to feed every ten of us?
Economic growth is overwhelmingly the proximate result of innovations that allow fewer workers to produce more output – thereby releasing that most precious of all resources, human labor, for use in producing goods and services that earlier were too costly to produce.
Donald J. Boudreaux