Two-thirds of the world’s population now lives in countries where the total fertility rate (TFR) – a measure of births per woman per lifetime – has dropped below 2.1, the number needed to keep the population constant.
This trend has surprised some demographers, many of whom have spent years worrying about an overcrowded planet. As recently as 2017, the UN was predicting that the world’s population – about eight billion today – would climb to 11.2 billion by 2100. It now predicts that it will peak at around 10.4 billion in 2080 and start declining; some demographers project that this will happen decades earlier. This would be the first such global-population decline since the Black Death in the Middle Ages. “The demographic winter is coming,” Jesús Fernández-Villaverde of the University of Pennsylvania told The Wall Street Journal.
Where is the birth rate dropping?
Almost everywhere. According to the UN, the global TFR had reached 2.3 in 2021; it will soon drop below the 2.1 replacement rate, if it hasn’t already. In the UK, the rate stands at 1.49, having dipped below 2.1 in the early 1970s. In Europe, the TFR is now 1.5; in East Asia, 1.2; in Latin America, 1.9.
Declining fertility used to be seen as a rich country’s problem, and to some extent it still is. The highest fertility rates in the world, of around five or six births, are in sub-Saharan African nations such as Niger, Angola and Democratic Republic of Congo. But now even poorer states have seen sharp fertility falls: not just China, whose population declined by two million last year as a result of the one-child policy imposed between the 1970s and 2015, but also, say, Iran or even India, where the TFR fell to two, below replacement level, in 2020.
What’s behind the drop?
There is a tendency to see it as a result of problems: economic insecurity, the high cost of housing, the expense of childcare. And certainly these have significant effects. But fertility rates almost always come down when nations reach a certain level of economic and social development, as a result of largely benign forces. This is known as “demographic transition”. Pre-industrial societies have high birth rates and high death rates. As sanitation and medicine improve, mortality declines and populations boom. Then, as infant mortality drops, birth rates stabilise.
Beyond that, birth rates are brought down still lower by other forces that many would also see as positive: the availability of contraception; the fact that women have similar educational and job opportunities to men; the decline in teen pregnancies (down in UK under-18s by more than two-thirds since the beginning of the century).
Why are people worried?
There are two main concerns. One is that people are having fewer children than they want: polls suggest that UK women on average want between two and three children. Second is the economic dimension. A shrinking population means that more jobs will go unfilled and economic dynamism will reduce. The most immediate fear is that welfare systems – which rely on people of working age to pay in and support the elderly – will be underfunded. Today, the G7 richest economies have roughly three people of working age for everyone over 65, but by 2050 they will have fewer than two. In South Korea, which has the world’s lowest fertility rate (0.72), the national pension fund is expected to run out of cash by 2055.
Can birth rates be boosted?
Governments around the world are trying, but nothing has been very effective. Japan has experimented with childcare subsidies and stipends since the 1990s. Its fertility rate climbed from 1.26 in 2005 to 1.45 in 2015, then sank to 1.2 again in 2023. South Korea has invested more than $270 billion in fertility initiatives since 2006, but its birth rate keeps declining. Hungary has seen some partial successes.
But the only really effective example of state action is one that liberal democracies would not want to emulate. In Romania in 1966, during Nicolae Ceausescu’s dictatorship, Decree 770 removed contraception from sale and restricted abortion. A baby boom followed; the fertility rate jumped from 1.9 to 3.7 within a year.
Don’t family friendly policies help?
To some extent. Some of the world’s lowest fertility rates are in nations where women play an important role in the workplace, but where traditional gender roles have endured, and where, until recently, there was little provision for maternity and paternity leave: for instance, Japan, South Korea, Italy (1.2) and Taiwan (0.8). But even the most family friendly nations on Earth have very low rates: Finland (1.32), Norway (1.4), Sweden (1.45).
It seems that the social trends behind low fertility are hard to reverse. People start their families much later now: in the UK, the average age of a woman when she has her first child is 32, ten years older than in the 1950s. Many people choose, to a greater or lesser extent, to prioritise career and leisure over family. And almost one in three UK homes were single-person households in 2023.
What other solutions are there?
Developed nations could – and already do – open their doors to immigrants from poorer nations with high fertility rates. This is, though, politically fraught. And the numbers involved would have to be very large to solve the economic problem. The demographer Paul Morland and the economist Philip Pilkington found that in order to maintain a “reasonable” ratio of working-age people to those aged over 65 into the middle of this century, it would require annual net immigration starting at 500,000, and rising over time.
Another solution is to start planning for smaller, older populations. Japan has started doing this: seeking, for instance, to automate as many roles as possible. There are, of course, some advantages to a falling population: less pressure on housing, more job security, and a smaller environmental footprint.