China announced today that it will end its "one-child policy," the radical measure that has barred many Chinese families from having multiple children since 1980. All couples will be permitted to have two children, as the country seeks to subdue the growing problem of a rapidly aging population and potential labor shortages.

The rule change marks another turn in the dramatic history of China's population. As the chart below shows, from Max Roser's Our World in Data, China's birth rate and death rate have swung wildly due to natural disasters, a man-made famine, economic development and, of course, the one-child policy.


Birth and death rate per 1,000 people. Max Roser, Our World in Data

In his early years as China's leader, Mao Zedong was actually in favor of people having lots of babies, to provide soldiers for its army and workers for its factory. "Of all the things in the world, people are the most precious," Mao wrote in 1949, quoting a traditional saying.

But Mao didn't hold this attitude for long. As China added 100 million people to its population through the 1950s, more and more officials began to advocate birth control. Leaders first instructed China's Women's Federation to start promoting birth control in 1953 and lifted bans on contraception and abortion in 1954. In the early 1960s, China introduced a variety of mostly voluntary birth control policies, according to Pieter Bottelier, a China expert and professor at Johns Hopkins School of Advanced International Studies. In 1975, the government told people to have "one child at best and two at most." The one-child policy wasn't introduced until 1980, by which time China's birth rate had actually already begun to drop.

The biggest drop in China's birth rate was due not to birth control, but the man-made tragedy of the Great Leap Forward from 1958 to 1961. That famine, and the demographic scar it left on China's population, is clearly visible in the chart above, where birth rates fall precipitously and death rates rise. According to new estimates, the famine may have killed 36 million to 45 million people.

You can see why China's population boomed in the 1960s and 1970s -- the birth rate per 1,000 people far exceeded the death rate. But by 2010, the gap between the two had narrowed significantly -- leaving China with a relatively large population of older people, and few younger workers to support them.

See also:

-China lifts one-child policy amid worries over graying population

-Why China is ending its one-child policy

-Why China’s single people need a hug, a donut — and Alibaba