Why has it taken so long for China’s population to shrink?
In 1991, within just a few years of the one-child policy kicking in, China’s birth rate had fallen to below replacement level. Each woman was having fewer children than the number required to maintain the population size from one generation to the next. In most countries, this is usually around 2.1 – one for each woman, one for her partner, and an extra 0.1 to counteract those that die as infants.
In the years that followed, China’s continued growth wasn’t because the controversial initiative had failed – it was down to a counterintuitive effect known as “demographic momentum”. This explains how a population with constant levels of mortality and zero migration can continue to increase for decades, even when women are having fewer than 2.1 children.
Why has it taken so long for China’s population to shrink? It’s all down to the time delay between births and deaths. Until recently, China’s population was relatively youthful, with an average age of 35 in 2010, compared to 44.3 in Germany (now it’s 38.4). At the same time, people have been living longer in 2021, the country’s life expectancy overtook that of the US. So, though the number of babies born per woman declined drastically, there were still more babies being born than there were people dying.
This has now changed, however. It’s thought that the drop in fertility rates and slight increase in reported deaths during the Covid-19 pandemic may have played a role in accelerating a decline in China’s absolute numbers, though it has been long anticipated.
According to the UN’s World Population Prospects report for 2022, China’s population was predicted to decline in 2023 the reduction recently revealed by the country’s census had been expected for some time. In fact, the demographic shift is only slightly early.
This milestone in China’s demographics has already been factored into many projections for global population growth. Based on the expectation that the country’s population would start to shrink in 2023, along with its predictions for other countries, the UN expects that the total number of humans on the planet will continue to expand, to reach 8.5 billion by 2030, and peak at 10.4 billion by 2086. This is the “medium” scenario, in which the birth rates of nations with high fertility will mellow, while those with low fertility rates will see marginal increases.
