Here is a lovely ad for Matt Ridley’s new book  and blog , The Rational Optimist. The ad captures the power of specialization and the division of labor in helping us eat better than the kings of yore. It doesn’t mention that a homeless person today gets better treatment for a heart attack than the President of the United States did 50 years ago. But it’s true and the ultimate source is the same, the power of exchange which underlies civilization. Without that exchange and specialization we couldn’t have developed the medical innovations of the last 50 years.