The truth about “baby busts” and population decline

Written by Olivia Nater | Published: January 16, 2024

Media stories on “baby busts” and “population collapse” abound, fueled by the fearmongering of pronatalist influencers who believe birth rates are too low. As a result, many people erroneously think our global population is in freefall, or even that humanity is heading towards extinction because people are having smaller families. This blog post sheds some light on declining birth rates and shrinking populations, and what these really mean for societies and economies.

Are we facing global population collapse due to low birth rates?

No. Contrary to what Elon Musk might have led you to believe, our world population of just over 8 billion is still very much growing. According to the most authoritative population projections, calculated every few years by the United Nations Population Division, we will likely pass the 9 billion milestone in 2037, and peak around 10.4 billion in the 2080s. The UN does not foresee any significant population decline for the remainder of the century.

What will happen after 2100 is much more difficult to project due to the high uncertainty associated with future demographic variables, including fertility (the number of births per woman), mortality, and longevity. While small changes in these variables don’t have big effects on population numbers in the short term, they can significantly impact population size several decades into the future. For example, the UN’s most likely scenario, called the medium variant projection, shows the global fertility rate reaching the replacement level of 2.1 live births per woman in 2055, and then continuing to decline to 1.84 in 2100, when our population size will be just under 10.4 billion. According to UN demographers, there is a 95% probability that our population in 2100 will be between 8.9 and 12.4 billion.

Other respected demographers have come up with slightly different population projections, but those that are lower than the UN ones usually assume accelerated progress in removing barriers to family planning and education. A set of projections by the Institute for Health Metrics and Evaluation (IHME) published in 2020, for example, forecast a population peak in 2064 at 9.7 billion, and a 2100 population size of 8.8 billion. The two main reasons these are lower than the UN projections is because the IHME researchers predict faster fertility declines in sub-Saharan Africa, as well as sustained low fertility in areas that are already well below the replacement level, whereas the UN assumes that fertility will increase again in some of these countries. The IHME researchers also calculated a very optimistic scenario in which the Sustainable Development Goals (SDGs) for education and family planning are realized ­— secondary education for all and zero unmet need for contraception by 2030. This scenario would yield an earlier peak and a population of 6.3 billion by 2100. Unfortunately, we are far off track for meeting these goals, so a population shrinkage of this extent is not likely.

Some researchers have also argued that even the UN’s medium population projection is too optimistic, because the assumptions about future fertility are not in line with recent trends in high-fertility countries — you can read more about this in the interview with Dr. Jane O’Sullivan for our December 2023 magazine issue.

It is clear that even the most optimistic scenarios would not yield a population “collapse” — the 25% decline relative to today in the above SDG scenario is significant, but the last time there were 6.3 billion people on Earth was in 2002, and no one complained about a serious people shortage then.

Of course, a real population collapse is sadly not impossible, but low birth rates will not be the culprit. Collapse would have to be driven by disaster on a massive scale, such as catastrophic environmental breakdown, deadly pandemics, or nuclear war. Let’s hope humanity will work hard to avert such an outcome.

So where is population declining?

Out of the 237 “countries” listed by the UN (including non-independent states, territories, and islands), 126 currently have below replacement level fertility, which leads to population decline in the absence of positive net migration. While the UN estimates that two-thirds of the world population now live in a country or area with sub-replacement fertility, the only regions of the world expected to experience an overall population decrease by 2050 are Europe, by 5%, and Eastern and South-Eastern Asia, by just 1%.

Globally, the 20 countries projected to experience the most rapid decline are all European, except for Japan and Cuba. Most of the European countries are located in Eastern Europe, where birth rates dropped rapidly following the dissolution of the Soviet Union, and where emigration rates are very high. Japan has been shrinking longer than any other country due to long-standing low fertility and low immigration. China joined the list of countries with declining populations just last year, when demographic data indicated it has likely reached peak population and has been taken over by India as the world’s new most populous nation.

Is population decline bad?

Some politicians have nationalistic reasons for wanting to boost population growth, such as a desire for ethnic, cultural, military, or economic dominance. More generally, the main reason governments, mainstream economists, and businesspeople fret about low birth rates and population decline is because these lead to population aging and fewer consumers and taxpayers, respectively. It is widely assumed that a larger proportion of older dependents and a shrinking base of working-age people means economic slowdown, and increasing strain on social security systems.

Economic concerns related to population decline have been shown to be overblown, however. In a 2023 paper, scientists looked at how some economic variables have changed in 19 countries with declining populations (most of them in Eastern Europe) between 1990 and 2019. The rate of population decline in these countries ranged from 28.1% in Latvia to 2.4% in Russia. In all study countries except Italy, both GDP and GDP per capita grew during this period, while the unemployment rate decreased in 16 of the 19 countries.

The authors concluded,

“…population reduction does not need to be disastrous economically. Hence the fears that economic stagnation will follow population decline may be unfounded.”

In an article featured in the September 2023 issue of our magazine, Dean Baker, a senior economist at the Center for Economic and Policy Research, argued that economic gains from increasing productivity negate the impact of a rising ratio of retirees to workers. He also pointed out that those concerned population aging will create too many dependents forget that babies are dependents too. In the U.S., for example, the combined young and old dependency ratio was highest in the early 1960s due to the baby boom.

Population aging certainly presents socioeconomic challenges, but these can be prepared for, such as through greater investment in preventive healthcare to keep older people fit and healthy for as long as possible. Countries need to face the inconvenient truth that relying on ever-larger cohorts of young people to sustain older generations is an unsustainable Ponzi scheme. We need to make our economic systems compatible with planetary limits.

Which leads to my final point, that ending population growth is absolutely essential if we are to avoid further escalating our environmental crises, from climate change to biodiversity loss to resource depletion.

Should we ever worry about declining birth rates?

Decreasing fertility rates generally reflect increasing bodily autonomy and education and career opportunities for women — developments that should be celebrated. The only situation in which low birth rates are grounds for concern is when people are having far fewer children than they would like to have, as seems to be the case for a growing number of couples, particularly in the Global North. Instead of aiming to increase fertility, policy efforts should have the goal of improving quality of life, reducing inequalities, and safeguarding the environment, which are key to removing the barriers that deter people from fulfilling their desired family size.