A demographic update: thoughts on world population day 2025

Happy 36th World Population Day, everyone.   This United Nations-decreed event asks us to consider demographics and I’ll do so in this post.  I’ll start with a recap of what we know and where we stand, then offer some futures reflections.  These will be macro, big picture discussions.

Three quick notes before we proceed.  First, demographics is a tricky subject to discuss.  The topic involves sex, bodies, personal choice, death, and religion, all easily capable of vexing us.  In the American context I call this the worst possible Thanksgiving dinner conversation. Additionally, in my experience of researching, talking, and writing about demographics I find a lot of people like to adhere to what they saw of demographics decades ago.  Second, and speaking of which, I’ve been working on this topic also for decades.  You can find plenty of posts on this site as well as material in some of my books.  Audiences in my talks know I love mentioning demographics because it’s an important tool in the futurist’s toolbox.  We can find plenty of data and analysis in the demographics field, as well as in the insurance industry and national policies.  Third, I’m going to focus on population ages for this post, because the topic is so deep.  Demographics of race, gender, ethnicity need their own posts.

To start with, recall the literally extraordinary boom in the human population in recent history.  For millennia the total number of people was relatively stable until increasing in the early modern era.  Then the first industrial revolution set in and woosh!

In my own lifetime (born 1967) the human population more than doubled.  The reasons are pretty clear: revolutionary improvements in public health, medicine, and agriculture helped more children live to adulthood. We gradually responded to this boom culturally and politically with anxieties and policies about overpopulation. You can see this in the historical record from movies and bestselling books to national population control efforts. I still hear people, mostly older ones, state that overpopulation is a major global crisis.

Then reality pulled the rug out from under all of that.  While the population and our fears shot up, women quietly stopped having so many children. Demographers offer a number, 2.1, which describes the number of children a woman must have during her lifetime for a total population to remain stable – not growing, not shrinking, but a plateau. Historically women have had higher numbers (5, 6, 9) and hence the population explosion. But childbirth rates have crept downwards or plummeted. Today in country after country that childbirth number is under 2, heading down to one.  At the same time people are living longer and longer lives.  The median age of populations has been rising.

The reasons for this development are pretty well understood. In a word, it’s modernity. Improvements in public health and medicine extended lifespans.  Women entering the workforce, receiving access to more education, and gaining more reproductive power drastically cut birth rates.  The decline in religious faith also played a role.

This is a gigantic transformation.  It’s nearly unprecedented, except for the worst plagues – and this time we are making it happen with our choices. Demographers blandly describe it as “the demographic transition.”

It’s also unevenly distributed around the world.  Roughly speaking nations which went through modernity then experience the transition.  You can see this at a glance in maps like this one:

Or this:

Note that number on the Statista map: childbirth globally fell to 2.2.  As a species we’re just about at the stability level.

You can see that many countries have fallen below replacement: most of North America, all of Europe, large parts of Asia and the Pacific world, much of South America. And you can see the nations still producing baby surpluses, India and central Asia, but notably in subSaharan Africa.  That’s where the demographic future lies for the next generation. That unevenness propels many political and economic strategies, like China’s One Belt, One Road which drives right through those regions.

The demographic transition has implications for nearly every aspect of life. There are economic impacts as the number of working-age people starts to dwindle, and as the retired population grows. This has already resulted in calls for changing (rising) the retirement age, cutting social services, and so on.  In America we’ve seen more and more people working after age 65; I fully expect to do so myself. Marketing may shift away from targeting teens and young adults as those populations dwindle. Cultures which see themselves as youthful may change. Rural areas, which tend to age and shrink faster than urban ones, may experience declines or cease to exist, becoming new ghost towns.

This is one reason international immigration is such a fraught topic. On the one hand there is the argument that nations seeing their working-age population shrink should import workers from the countries still producing people at scale.  During the Cold War West Germany did this with Turkish workers in their Gastarbeiter program.  In the United States we see something similar where farms in areas lacking would-be workers employ migrants for agricultural work.  Of course, this is also a way to hire staff for less pay, as people coming from the developing world/global south are more likely to accept lower compensation. Famously (or notoriously) such demand for immigration also elicits anti-immigrant sentiment and politics, which we now see in many national governments, including my own.

This ties into a rising natalist movement, as I’ve long been forecasting.  Some nations have tried to grow their fertility rates through various means, like giving tax breaks or awards to mothers.  I’m fond of Denmark’s ad campaign to send young couple on holiday to have sex.  “Do it for mom” is the slogan.  Seriously, I’m not making this up:

All of the efforts have flopped. The natalist movement, which seems small right now, wants to succeed where they failed, through a mix of government subsidies and culture war nostrums. Naturally there are various cultural and political currents intertwined here, from racism (have more children of the race we prefer) to religion (be fruitful and multiply) to sexism (seeing women as primarily baby machines).  Others argue for economic reasons (have more kids to become workers and taxpayers). Still others call for more people to increase chances of more exceptional talents arising.  Bryan Caplan says large families are just personally, even selfishly awesome.  You can see how the demographic transition weaves through so many issues and beliefs.

On another yet related front, Darrell Bricker and John Ibbitson have argued that shrinking and aging nations might be less likely to go to war, a state of affairs they dubbed “geriatric peace.”  John was a great guest on the Future Trends Forum back in 2020:

Bricker and Ibbitson brought up an additional wrinkle in the problem, noting that the United Nations’ population projections have repeatedly been too high.  Marc Novicoff recently noted the same:

Every two years, the UN’s demographers revise their population projections, and for the past 10 years, they’ve always had to revise in the same direction: down. Next year, they’ll do so again. In reality, the worldwide population decline is set to begin decades ahead of their expectations. Because global fertility trends are much worse than they, and probably you, think.

Like I said, this is a hard topic to discuss and reality just keeps pulling the rug out from under many of us.

So when does the total population plateau, then decline, reversing a centuries-old course?  When is peak human, at least in terms of sheer numbers?  The total won’t fall right away because of “population momentum,” the fact that it takes time for people to age and for societies to experience this transition. The United Nations thinks we’ll max out in the 2080s at just over 10 billion of us.  Another group of researchers project an earlier date: “the global population was projected to peak in 2064 at 9·73 billion (8·84–10·9) people and decline to 8·79 billion (6·83–11·8) in 2100.”

What might this world look like?  I’ve already mentioned some of the cultural and political responses starting to appear.  We can think of others.  We might see struggles over (potentially shrinking) public funds between services for elders (growing) versus children (dwindling).  What might happen to the built environment – repurposing elementary, then secondary schools as elder care facilities, or turning depopulated towns back to nature a la EO Wilson’s half Earth idea?  How will we react to the glimpse of societies and nations ending?  Will we see cultural clashes over ageism, as employers compete for fewer younger workers and try to avoid hiring more expensive seniors?  Will fewer new ideas surface, as some have argued, or will we support more innovation stemming from older folks? Will women still have access to reproductive capacity or will more governments and civil society actors seek to block it for demographic reasons (among others)? Will assisted suicide become more accepted by people impatient with large bodies of elders? As some rural regions decline, will cities continue to grow in response, accelerating urbanization?  I can imagine several vast cities surrounded by large areas large empty of people as nature reclaims towns, inhabited by people nominally retiring at 75 but often working past that point. I can also envision governments defaulting on debt and declaring bankruptcy when they can no longer manage their new economic order.

This is one reason for the major push to develop robots.  If there are fewer human workers, why not build more machines to do their jobs?  We’ve already done quite a bit of this in some manual labor sectors, like automotive construction, and there is a lot of R&D going on to go beyond that. We’re already seeing robots used in policing, war, food service, deliveries, and more. Perhaps we’ll see the same successfully deployed in care services – already New York state claims its use of companionbots for isolated elders is working well. Imagine cities where robots outnumber people in streets and homes, where single individuals manage a swarm of robots to help them with the many functions of life, including personal interaction. Consider a world where a substantial number of people prefer the automated machine world to humans and such preferences further drive down childbirth. However, robots do not pay taxes nor spend money into the economy, making them only a partial solution.

And obviously the demographic transition impacts education. Start with primary schools, where numbers fall wherever the transition occurs. Secondary schools follow suit in just a few years. Class sizes can shrink, which may be great news for instructors and students alike, but this may also lead to reducing the number of teachers or closing schools.  I experienced this in Vermont during the 2000s and 2010s, a state which raced through the demographic transition in a hurry, yielding a big, bipartisan push to cut K-12 spending and to close schools.

Higher education is next, starting with campuses which focus on traditional-age (circa 18-22 years old) undergraduates.  Their pipeline shrinks, which triggers more inter-institutional competition. Those who lose out face program and staff cuts, mergers, or closures, as we’ve seen and I’ve been recording.  Some of these colleges and universities may pivot to teach more adult learners, as some schools (community colleges, open enrollment state universities) already do. Perhaps some will reach out to teach senior citizens, as I’ve been urging.  Will we see education departments, which prepare K-12 teachers, decrease while health care programs aimed at senior citizens boom? Funders and state governments are very aware of the demographic transitions and make education policies accordingly.  As I saw in Vermont, it is hard to make the case for maintaining a certain educational system in the face of demographic changes.

Let me close with my typical futurist’s caveats.  None of this is 100% certain, as people are creative creatures capable of all sorts of things.  Perhaps the Natalists will score a cultural victory and convince women to have more children, although I think this very unlikely. Maybe conservative religious believers will in the generations to come become more culturally and politically powerful and drive up fertility through various, some dystopian means.  We might invent and build out artificial wombs, as Shulamith Firestone called for, and use them to produce children without women giving birth.  The natural world may, of course, have its way with us, perhaps sending another pandemic to brutally cull swathes of the species. That might accelerate the childbirth decline while cutting down seniors, and might in years to come yield a baby boom as a devastated world seeks to recover.

Speaking of nature and humanity, climate change plays many roles in the demographic transition. Some may – and do – celebrate a reduction in the human race as it might reduce our greenhouse gas emissions.  Perceptions of climate stress and disasters can drive immigration from afflicted areas, feeding into the migration challenges mentioned above.   Some of the most endangered regions, like Sub-Saharan Africa, may suffer population loss due to climate-driven storms, heat increases, floods, and more.

One last note on this World Population Day. I think the demographic transition we’re living through and which will transform civilization plays a key part in what I’ve called the emergence of two competing ideologies of the future.  Briefly, one side seeks to continue the industrial revolutions’ exceptional growth on all kinds of metrics – science, technology, lifespan, projection of power, educational attainment, space exploration, etc. – and therefore wants us to keep growing the human population. The other wants us to pause or shrink our civilization, either because it’s morally the right thing to do or because systemic problems will force us to. This side celebrates the dwindling of humanity’s population as a force for good in the natural environment, as well as for personal liberation and social justice.  And perhaps they’ll see interpret an economic decline caused by fewer workers as a benign goad for degrowth. Neither side has formal names yet (I’ve been working with “hypermodernist” and “demodernist”), but I think you’ll see their competing worldviews surface more and more as we work through this vast transformation.

If you’d like to read more about this topic, I recommend a good essay by Nicholas Eberstadt.  Keep thinking about demographics, everyone.