OF ALL the institutions of modern China, the one that most famously reflects the Communist Party’s determination to control its population is the one that literally does so: its one-child policy. The enforcers of family planning (the bureaucracy numbers about 500,000 now) have been a formidable presence in every town across China for more than 30 years. Now those enforcers will be processing a different kind of paperwork: couples where one parent is an only child (as opposed to both) will be allowed to have a second child. The change, decided by the Communist Party Central Committee at a plenum last month, affects an estimated 10m to 12m families, and experts figure up to half might choose to take the party up on the offer. Provinces are allowed to implement the change on their own timetable, but they have been urged to do so quickly. Why is China relaxing its one-child policy? Most say it is long overdue. Critics have long viewed the one-child policy as an outdated and archaic tool of social control and a legacy of Mao’s disastrous efforts to impose a new order on society. It is a bit of a strange case historically, because the one-child policy actually came into being after Mao died, during China’s era of reform and opening. At a time when the Communist Party was mostly retreating from private lives, it chose to intrude forcefully in this most personal realm of reproductive health. Communist Party leaders suffered from a Malthusian fear that if left to their own devices the people would multiply beyond the country’s ability to feed itself. Many demographers, including Chinese experts, feel this fear was unfounded. The party claims it has saved 400m births with the one-child policy; many demographers put the number at more like 100m, as the birthrate was beginning a sharp decline even before the policy went into effect in 1980. (This decline continued despite a number of exceptions to the one-child policy, especially in rural areas.)

In the end demography was the reason Chinese leaders had to act. China’s fertility rate of 1.5 to 1.6 children per woman is below the replacement rate (of about 2.1), and the fertility rates in the biggest Chinese cities are among the lowest in the world at well below 1.0. The demographic costs are becoming painfully obvious. China’s labour pool declined in 2012 (by 3.45m) for the first time in almost 50 years. The ratio of taxpayers to pensioners is expected to drop from almost five to one to just over two to one by 2030. China now faces a different population fear than Malthus imagined: a quickly aging society with too few young people to support their parents and grandparents. Chinese demographers, including some who advise the government, believe the policy should have been relaxed long ago—if not, a few dare to say, scrapped altogether. A move this March to combine the family planning bureaucracy with the health ministry gave hope to some that the one-child policy was in its twilight.

The populace would certainly welcome a dismantling of the family planning system. Tales of abuses—including of forced late-term abortions—still surface every now and then, and they reverberate much more loudly and angrily in the age of social media. Yet there seems little chance the entire policy and its enforcers will disappear soon. The next step would be to move to a national two-child policy, once leaders feel assured that giving the people a bit more reproductive freedom will not make the sky fall in. They needn’t worry. Surveys show that many parents in cities want only one child anyway. The increasingly high cost of a few extra square feet of housing, not to mention of providing a good education, also makes it economically harder to justify more children. The facts of modern life rendered the one-child policy obsolete long before China’s leaders dared tinker with it.