The More Men, the More Chickens

Betting on the Planet, this 1990 classic by John Tierny, is still freely available on the New York Times website.

This idea marked the crucial difference between Simon and Ehrlich, and between economists and ecologists: the view of the world not as an closed ecosystem but as an flexible marketplace. The concept of carrying capacity might make sense in discussing Ehrlich's butterflies or Vogt's "Gadarene swine," but Simon rejected animal analogies. He liked to quote the 19th-century economist Henry George: "Both the jayhawk and the man eat chickens, but the more jayhawks, the fewer chickens, while the more men, the more chickens."