Chinese officials are fiercely attached to the one-child policy. They attribute to it almost every drop in fertility and every averted birth: some 400m more people, they claim, would have been born without it. This is patent nonsense. Chinese fertility was falling for decades before the one-child policy took effect in 1979. Fertility has gone down almost as far and as fast without coercion in neighbouring countries, including those with large Chinese populations. The spread of birth control and a desire for smaller families tend to accompany economic growth and development almost everywhere.
But the policy has almost certainly reduced fertility below the level to which it would have fallen anyway. As a result, China has one of the world’s lowest “dependency ratios”, with roughly three economically active adults for each dependent child or old person. It has therefore enjoyed a larger “demographic dividend” (extra growth as a result of the high ratio of workers to dependents) than its neighbours. But the dividend is near to being cashed out….