STEVEN E . LANDSBURG PEOPLE PARADOX

After a long argument, Simon challenged Ehrlich to select five metals and a date in the future, betting that the price of the selected metals then would be lower than at the time of the wager, suggesting more availability rather than scarcity. [...] There’s a limit to the number of people that the earth can support.’ That’s someone who has contributed nothing to under- standing the question because we all know that there’s a limit to the number of people the earth can support, and so there is such a thing as ‘too many people’. [...] What are the benefits and costs they are accounting for, and what are the benefits and costs that spill over onto other people? I’ll call the private benefits and costs the ones that the decision makers feel directly, the ones of which the parents are aware. [...] The character of Ted was played as a clown, and he used to say on the show that he was planning to have twelve children in the hope that one of them would grow up to figure out how to solve the world’s population problem. [...] In fact, a team of economists at the Richmond Federal Reserve Bank has made an intriguing case for the propo- sition that the Industrial Revolution, and the tremendous culture of innovation that grew out of that, had to wait until the world population was large enough to reward large-scale inventiveness.