Covid baby boom or not, what do demographers predict for this century?

Will one side-effect of the Covid-19 pandemic be a rise in fertility? It seems quite possible that the lockdown will have encouraged young people to become parents, even if unintentionally. Whether there is a Covid baby boom or not, though, what do demographers predict for the rest of this century?

Any baby boom is likely to be a temporary blip rather than a new trend. The total fertility rate in Britain has been falling: according to the Office for National Statistics (ONS), in 2019 the average woman had 1.65 children in her lifespan, down from 1.7 in 2018. Fertility has been below the replacement level of 2.08 since 1973, when the mean age of mothers at childbirth was 26.4 years; it is now 30.7 years. Other things being equal, older mothers mean fewer babies. And fewer babies mean a smaller workforce to support our ageing population.  

At present, total births still exceed deaths, but probably not for much longer. According to the Migration Observatory at the University of Oxford, the population of England will grow by 10 per cent over the next 25 years, but most of this increase is due to net international migration. The ONS calculates that, without immigration, the UK population would begin to decline from 2028.  

How does the UK fit into the global picture? The world of demography has been debating a new study from the highly respected Institute of Health Metrics and Evaluation (IHME) at the University of Washington. This challenges the generally accepted UN analysis, which expects global population to peak around the year 2100, by suggesting that populations in more than 150 countries will be declining by 2050. According to the IHME study, global population will peak at 9.73 billion as soon as 2064 and thereafter decline to 8.79 billion in 2100. By then, Japan, Italy and Spain will be among those to see their populations fall by at least half. Thanks to immigration, Germany will only decline from 83 million to 66 million, but in Central and Eastern Europe, some countries are predicted to plummet by up to two-thirds.

Most dramatic will be the fortunes of China, which will overtake the United States to become the world’s largest economy by 2035, but then fall behind again as its population collapses from 1.6 billion to just 730 million in 2100. The United States is predicted to have much the same population by 2100 as it does today, growing from 324 million to 335 million. This obviously has huge implications for the geopolitic al rivalry between the two superpowers.

India will still have more than a billion people, making it the most populous on earth, though its fertility rate will show the largest fall of all. And Nigeria will overtake China to have the second largest population, exploding from 206 million today to 790 million by 2100. As the global population ages, the working age population will continue to decline in comparative terms. Each worker now has to support 0.8 non-workers; by 2100, this figure will rise to 1.16. By far the largest number of workers — and hence migrants — will come from sub-Saharan Africa.

The IHME explains that, unlike the UN, its predictions assume that global population will decline as women take more control over their fertility. As countries with rising populations tend towards the mean, their fertility may fall to 1.5 or lower, meaning that global population could fall more rapidly than they predict.

What does the IHME study tell us about the UK? It predicts that the British population will rise gently from 66 million today to 71 million in 2100. Despite this gradual increase is likely to witness considerable fluctuations over the rest of this century, mainly due to migration, and it is quite possible that before mid-century the UK could be home to 80 million people or more.

One potentially important factor is the decision to offer a path to citizenship to nearly 3 million Hongkongers with British Overseas passports. This is a lifeline for those, mainly young, people there who see no future for themselves now that Beijing appears to be abandoning the “one country, two systems” principle. But the arrival of large numbers of highly educated, working-age Hongkongers would also be a shot in the arm for the British economy.

On the Andrew Marr show last weekend, the Chinese Ambassador to the UK assured viewers that Hongkongers were free to leave. But his government has also expressed its anger at the British offer, which it sees as interference. Given China’s prospective demographic decline, is it likely that Xi Jinping will permit millions of young Hongkongers to emigrate to the UK or other Western democracies? As populations age, migration may increasingly be seen as a zero-sum game: my loss is your gain. At the very least, the Chinese are likely to make it more difficult for the young to leave for the West. If they do, however, they will ultimately fail, just as the Soviet Union tried and failed to stop Jewish “refuseniks” emigrating to Israel.

The only country in Europe that has succeeded in reversing its decline in fertility this century is Sweden, from 1.5 to 1.8 children per woman. The IHME study predicts that Sweden’s population will rise from about 10 million today to 13 million in 2100. How much of that rise is due to state support for families and how much to immigration is a moot point. But it is striking how much more generous than the UK other European countries are to young mothers.

Demography is not destiny, however neat it may sound. On the contrary, demography is a human science, not an exact one. Predictions are notoriously difficult and may be falsified both by known unknowns — such as migrations, wars and pandemics — and unknown unknowns, which are by definition unknowable today. In 1920, nobody predicted the world of 2020. But many people born today will still be alive in 2100. It isn’t that far away. If there is a Covid baby boom, that is something to celebrate, not deplore. As a society, we owe a duty to posterity to make newborns and their parents as welcome as possible. After all, one day we are all going to depend on them.