IN THE cherry-tree-studded hills a couple of hours south-east of Seoul sits a bungalow-style school building made of dark bricks. Its wooden floors are lovingly polished. The brightly coloured walls are lined with books and toys. The only thing it is missing is children. Forty years ago, in the region’s heyday as a mining area, Bobal primary school had more than 300 pupils. Today it has three: one girl and two boys, looking forlorn among the empty chairs. The school is only being kept open because a handful of villagers mounted a campaign to resist the education ministry’s plan to merge it with the one in the next town, ten kilometres away. “Keeping the school is important for the community,” says Kim Jung-hoon, whose daughter is one of the three pupils left. “How will we ever persuade families to stay if there is nowhere to go for their children?”

But the education ministry’s plan, which Mr Kim and his fellow activists see as an assault on their village, is a symptom of a wider trend. Since the early 1980s more than 3,500 schools have closed; 28 are set to do so this year. The reason is that South Korea is running out of children. The fertility rate, which suggests how many children the average woman will have over her lifetime, stood at just 1.05 last year, the lowest in the world and far below the “replacement rate” of about 2.1 needed to sustain a population. In Seoul, the capital, the rate is just 0.84. Though South Koreans are not as old as their Japanese neighbours, they are ageing faster.

Most demographers blame a growing mismatch between traditional mores and the changing preferences of younger people. Women are now more educated than men and are keen to succeed in the workforce, despite entrenched sexism and a huge gender pay gap (the average South Korean woman makes just 63% of the salary of the average man). The long hours and rigid hierarchies in South Korean businesses mean that family life is not easy to fit in, even for men. But women face more hurdles. “Many companies still see women as temporary workers who will drop out as soon as they have children,” says Lee Do-hoon of Yonsei University. “So women worry that they won’t be able to return to their jobs after starting a family.”

Affording a family is difficult. Unemployment among young people stands at 10.5%. University graduates, who make up 69% of those between 25 and 34, can no longer expect to walk into a lucrative job and keep it for life. Owning a house in Seoul, where most economic opportunities are, is out of reach for all but the richest.