Noahpinion

This is a big problem. The first fertility transition was a good thing — it was the result of the world getting richer, it saved human living standards from hitting a Malthusian ceiling, and it seemed like with wise policies, rich countries could keep their fertility near replacement rates. But this second fertility transition is going to be an economic catastrophe if it continues.

The difference between a fertility rate of 1 and a rate of 2 might seem a lot smaller than the difference between 2 and 6. But because of the math of exponential curves, it’s actually just as important of a change. Going from 6 to 2 means your population goes from exploding to stable; going from 2 to 1 means your population goes from stable to vanishing.

Shrinking populations are continuously aging populations, meaning that each young working person has to support more and more retirees every year. On top of that, population aging appears to slow down productivity growth through various mechanisms. Immigration can help a bit, but it can’t really solve this problem, since A) when the whole world has low fertility there is no longer a source of young immigrants, and B) immigration is bad at improving dependency ratios because immigrants are already partway to retirement.