The Puzzle of the Other Hockey Stick
28th July 2013
David Friedman thinks of cool stuff so that you don’t have to.
Malthus started with the observation that humans like sex, and sex produces babies. He concluded that, unless there were large costs to producing babies, population would increase at something close to the biological maximum, leading to an exponential growth rate high enough to overcome any plausible rate of increase in human productivity. Looking around him, he observed that most people were poor enough so that the cost of supporting an additional child was a substantial burden. He concluded that if that was not the case, if, as Godwin and Condorcet, the authors he was responding to, expected, the future saw a sharp rise in the standard of living of the masses, making additional children only a minor burden, population would increase rapidly and the pressure of population against a fixed supply of land would push standards of living back down.
It’s an elegant argument and provides a plausible explanation for most of human history, but one that stopped working within the lifetime of its author. Why? What went wrong with Malthus’ model?