‘One child is enough’: What’s behind the West’s baby bust

VILARDEVÓS, Spain — Nestled in the scrubby hills of northern Spain, this small village feels like a place that has fallen out of time. In reality, it offers a glimpse of the demographic future. When Yaiza Ferreiro Collazos begins her English lesson on a June morning, eight children are sitting in front of her. The oldest are in sixth grade, the final year of primary school; the youngest are in fourth. Teaching them together is not always easy, the 30-year-old says. But there are too few pupils to separate them. The Rodolfo Núñez Rodríguez nursery and primary school opened in 1974 and was built for 700 children from Vilardevós and the surrounding villages. Today, it has 31 pupils, from preschool through sixth grade. Apart from the school bell, the building is eerily quiet, even during breaks. The silence extends into the village. Most people encountered in its lanes are old. Many houses are abandoned, their façades marked with signs reading Se vende — for sale. Vilardevós is an extreme case, but not an isolated one. Across Europe, birth rates are falling, populations are aging and fewer young people are entering the workforce. Modern welfare states rest on an intergenerational bargain. Today’s workers finance pensions and health care for older people, trusting that others will eventually do the same for them. Low fertility is straining that bargain. Fewer young people are entering the workforce just as large generations approach retirement. Pension reform has already become one of Europe’s most politically difficult issues, and the viability of the Social Security system is a perennial concern in the United States. Those political pressures will continue to intensify as the population ages. That has forced governments to confront an increasingly urgent question: Can they persuade people to have more children — and, if not, can immigration prevent the demographic arithmetic from breaking down? Why birth rates are falling For a population to remain stable over time without immigration, women must have an average of about 2.1 children. According to the latest Eurostat data, the European Union’s fertility rate — the average number of children a woman is expected to have over her lifetime — fell to 1.34 in 2024. In Spain, the lowest among the continent’s large countries, it was 1.1 and still declining. The United States is only slightly less exposed. Its fertility rate, long higher than Europe’s, has also dropped well below replacement level. According to the Centers for Disease Control and Prevention, it fell to 1.6 in 2024. For a long time, falling birth rates were not treated as an urgent problem. After all, their effects take decades to emerge: A decline in births does not become a shortage of workers until roughly a generation later. By the time schools empty and pension systems come under strain, the demographic trajectory is set. Europe and the United States also appeared less exposed than parts of East Asia. Taiwan, Hong Kong and Singapore are already grappling with fertility rates below one child per woman. Then there is the harder question: Why is this happening? There are many competing explanations. Karen Benjamin Guzzo, a sociologist at the University of North Carolina, has argued that part of the fall in the U.S. reflects a public-health success: Americans have become better able to avoid teenage pregnancies and unintended births. But beyond that, the story is similar on both sides of the Atlantic. Housing is too expensive. Women are prioritizing their careers. Men are taking longer to mature. Religion has lost influence. Smartphones and social media are weakening real-world relationships. Fear of climate change makes having children feel useless and cruel. Each hypothesis has its adherents, along with its own books, podcasts and preferred evidence. None, on its own, fully explains the decline. Berkay Ozcan, professor of social and public policy at the London School of Economics, has little patience for attempts to ide