In 1980, Julian Simon, then a professor at the University of Illinois, placed a bet with Stanford University professor Paul Ehrlich and two of Ehrlich’s colleagues. The wager involved the future price and availability of five metals. Simon bet that the price of these metals (adjusted for inflation) would be lower in 1990 than they were in 1980, indicating that they were not scarce resources. Simon won the bet.

The wager was one of the most publicized examples of the opposing views Simon and Ehrlich had of the environment and the future of the planet. Simon had long argued that the environment and living conditions were improving and would continue to do so. According to Simon, human intelligence and ingenuity were the keys to improving the environment. He wrote: “Human beings are not just more mouths to feed, but are productive and...