Which country has the most people?

India, which passed China in 2023 - the first change in that position in centuries. Both are around 1.4 billion, and the crossing point is estimated rather than observed, since India's last completed census was in 2011 and the one due in 2021 has been repeatedly postponed.

The reason for the swap is not that India is growing quickly. Its fertility rate has fallen below replacement level, to around two children per woman, which is one of the faster demographic transitions on record and happened without the coercion China used. India's population is still rising only because of momentum - a young population means many people of childbearing age even when each has few children.

China's decline is the sharper story. The one-child policy ran from 1980 to 2015, and the fertility rate is now around one, well under half of replacement. The population began falling in 2022 and projections have it dropping by hundreds of millions this century, with a rapidly ageing workforce supporting a growing retired population. Ending the policy has not reversed it - a pattern seen everywhere, which is that fertility is much easier for a state to suppress than to restore.