DEMOGRAPHY: China’s Achilles Heel. “Over the past 30 years, China’s total fertility rate—the number of children a woman can expect to have during her lifetime—has fallen from 2.6, well above the rate needed to hold a population steady, to 1.56, well below that rate (see table). Because very low fertility can become self-reinforcing, with children of one-child families wanting only one child themselves, China now probably faces a long period of ultra-low fertility, regardless of what happens to its one-child policy. . . . In 1980 China’s median (the age at which half the population is younger, half older) was 22. That is characteristic of a young developing country. It is now 34.5, more like a rich country and not very different from America’s, which is 37. But China is ageing at an unprecedented pace. Because fewer children are being born as larger generations of adults are getting older, its median age will rise to 49 by 2050, nearly nine years more than America at that point.”