Jesus Fernandez-Villaverde

For anyone tempted to try to predict humanity’s future, Paul Ehrlich’s 1968 book The Population Bomb is a cautionary tale. Feeding on the then popular Malthusian belief that the world was doomed by high birth rates, Ehrlich predicted: ‘In the 1970s hundreds of millions of people will starve to death.’ He came up with drastic solutions, including adding chemicals to drinking water to sterilise the population. Ehrlich, like many others, got it wrong. What he needed to worry about was declining birth rates and population collapse. Nearly 60 years on, many predict the world will soon reproduce at less than the replacement rate. But by my calculations, we’re already there. Largely unnoticed, last year was a landmark one in history.