How many people live in China?

How to get close to this number

Two countries sit above a billion and everyone else is far below, so the only question is which of the two is larger and by how much. They are within a few percent of each other, which puts both in the low-to-mid one-point-four billions — and the explanation resolves the ordering.

The direction of change is what people get wrong. This population has been shrinking for several consecutive years, which is a genuinely new condition — a country of this size has never contracted in the modern era. Anyone extrapolating from decades of growth will estimate too high and, more importantly, will misread where the country is heading.

The causes in the explanation are the interesting part: decades of restrictive birth policy followed by a collapse in births that continued even after the policy was scrapped. That is the important finding — removing a restriction did not restore fertility, because the economic and social conditions that suppress births had changed independently. Policy created the decline and could not reverse it.