Peter Franklin is Associate Editor of UnHerd. He was previously a policy advisor and speechwriter on environmental and social issues.

South Korea is a remarkable country. From the devastation of the Korean War in the 1950s, it grew and grew to become one of the world’s richest nations – a high tech, exporting powerhouse and a model of industrial development.

Furthermore, it pulled-off this success story in the toughest of neighbourhoods. As well as sharing a peninsula with North Korea it has China to its west and Japan to its east. To the south, the sea is roiling with geopolitical tensions.

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And yet the greatest danger facing South Korea comes from within. Quite simply, the country’s birth rate is catastrophically low.

It’s the subject of an article by Crystal Tai in the South China Morning Post:

“South Korea’s birth rate is also the lowest in the world, dropping to 0.95 at the end of last year – meaning that for every 100 women, just 95 children were born. To maintain a stable population, the birth rate needs to be 2.1. In the boom times of the early 70s, nearly 1 million South Korean babies were being born each year, but by 2017 that number had more than halved to 357,700.”

Birth rates of well below replacement level are now commonplace in the developed world. For instance, Italy’s is about 1.4. If such a rate is maintained over three generations then that means the second generation will be 70% of the size of the first, and the third generation half the size of the first. That’s quite the demographic slide, but consider what happens if the birth rate drops even lower to approximately 1. If that is maintained over three generations, then the second generation will be half the size of the first, and the third a mere quarter. In other words a fall in the fertility rate from 1.4 to 1, which South Korea shows is possible, doubles the rate at which new generations halve in size.

Think through the implications. Cast your mind forward 50 or 60 years and imagine what it would mean for schools, universities and the workforce. Yes, in some places, domestic and international migration could be a temporary compensating factor – but only at the expense of accelerating demographic decline in the regions and countries of origin.

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What explains the fall in South Korean birth rates? Tai looks at the proximate causes:

“Yet despite this near-constant push to marry, an increasing number of South Koreans are forgoing weddings altogether. In fact, many don’t even date any more. “A survey by the Korea Institute for Health and Social Affairs published in early January found that as of 2012, the latest year for which figures are available, less than 40 per cent of 20- to 44-year-olds were actively dating. The proportion in traditional marriages is even lower.”

As for the deeper causes, Tai mentions the average $90,000 cost of getting married and South Korea’s long working hours:

“OECD data showed that in 2017, the average South Korean worked nearly 250 hours more than counterparts in the US, and 424 hours more than those in Germany.”

There’s also criticism of a patriarchal culture in which women are burdened with unfairly shared responsibilities at home and discriminated against in the workplace.

These factors may explain why South Korea has an especially low birth rate, but it’s worth remembering that birth rates are also falling in the most progressive, sexually egalitarian parts of the world – such as the Nordic countries. Even Finland, with its ‘baby box’ package of support for new parents and its impressive schools, has seen its birth rate hit record lows.

One of the most interesting countries to look at demographically is China. After decades of deliberately working to reduce its birth rate, most notoriously through the oppressive one child policy, the government has realised it may have overdone things. Since 2016, a two child policy has been in force, but the Chinese people are not rushing to take advantage of this new freedom. According to a report in the New York Times by Steven Lee Myers, Jin Wu and Claire Fu, there are fears that an already low fertility rate is heading lower:

“After a brief uptick that year, the birth rate fell again in 2017, with 17.2 million babies born compared to 17.9 in 2016. Although the number of families having a second child rose, the overall number of births continued to drop. “According to preliminary official figures cited by The Global Times, a party-run newspaper, the total number of births for 2018 could fall to as low as 15 million. Some cities and provinces have reported declines in local birth rates of as much as 35 percent.”

Some experts believe that the official fertility rate of 1.6 does not reflect reality:

“Yi Fuxian, a professor at the University of Wisconsin-Madison, has written that China’s government has obscured the actual fertility rate to disguise the disastrous ramifications of the ‘one child’ policy. According to his calculations, the fertility rate averaged 1.18 between 2010 and 2018.”

If this is correct, then it’s world-changing stuff.

We talk about the ‘greying’ of populations due to increasing longevity, but the biggest story is not one of improved retention, but a collapse in recruitment. The fact that birth rates are lowest in the east Asian economies that have low levels of compensatory immigration, but which are also relied upon as the drivers of global economic growth, has implications for everyone.