Shang-Jin Wei in Project Syndicate:
China’s recently released population census confirms the persistence of the country’s alarming excess of males relative to the global norm. This numerical imbalance from birth onward has several significant economic implications – and not only for China.
Because women live longer than men on average, most countries’ populations have more females than males. In the United States, for example, there were 96 males per 100 females in 2020. China, by contrast, has 105 males for every 100 females, according to the latest census. Chinese women live about three years longer than Chinese men on average, so the “excess males” are entirely the result of an unusually high ratio of boys to girls at birth.
The sex ratio at birth is normally around 106 boys per 100 girls. Because boys and young men have a slightly higher mortality rate, and because husbands tend to be somewhat older than wives, such a ratio at birth is nature’s way of ensuring a roughly 1:1 ratio by the time they reach reproductive age.
Although China’s male-to-female ratio at birth was close to this natural rate in the 1970s, a combination of factors fueled its steady rise.