The Malthusian Kneejerk Reaction to Urbanization

When you have high infant mortality with half the children dying very early in life, if you want three kids, you need to have six. But also the big driver is when you get urbanization and people start moving to cities. Children are an expensive hobby in a city. They don't actually bring any economic return until they're in their 20s of life. It's a very expensive pastime having children. And so shockingly, all over the world, as people move into cities and sort of figure out the dynamics of urban life, their behavior changes. There are fewer children and as birth control and so on, it's become more widely accessible. We see more and more of that.