What’s up, or down, with world population?

Chris Armstrong has a post at Crooked Timber with the intriguing title, What if there were far fewer people? (Jan. 8, 2023). The article opens:

One of the most common arguments in debates about environmental crisis is: “it’s the rising population, stupid.” There are just too many human beings, using up too much stuff, leaving too little space for everyone else. The next step is often to gesture towards some kind of population control, or just to leave the issue hanging.

Whatever you think of that position, I’ve been struck lately by the increasing prominence of its diametric opposite. This holds that the problem we face – or will soon face, anyway – is that there are actually too few of us.

It has attracted 89 comments so far. I rather like this one by engels:

The reason Western political classes worry about population isn’t anything long-term but that in the structure of housing markets, careers and welfare systems Western economies are basically Ponzi schemes, that require a continuous stream of enthusiastic twenty-somethings to keep the balls in the air. That be can purveyed either by breeding or immigration, which are (un)popular with different constituencies.

Setting that aside, Armstrong then links to this article: Dean Spears, The World’s Population May Peak in Your Lifetime. What Happens Next? NYTimes, Sept, 2023.

Spears points out that, if current trends in population growth continue, the world’s population is likely to peak at about 10 billion late in this century, around 2085, and then begin to decline. Why would it decline? Because people throughout the world are choosing smaller family sizes.

Any worldwide average of fewer than two children per two adults means our population shrinks and in the long run each new generation is smaller than the one before. If the world’s fertility rate were the same as in the United States today, then the global population would fall from a peak of around 10 billion to less than two billion about 300 years later, over perhaps 10 generations. And if family sizes remained small, we would continue declining.

I must admit, that doesn’t bother me very much. I see no inherent virtue in a large population and am inclined to think that reducing humanity’s drain on world resources would be a good thing. However:

Over the past 200 years, humanity’s population growth has gone hand in hand with profound advances in living standards and health: longer lives, healthier children, better education, shorter workweeks and many more improvements. Our period of progress began recently, bringing the discovery of antibiotics, the invention of electric lightbulbs, video calls with Grandma and the possibility of eradicating Guinea worm disease. In this short period, humanity has been large and growing. Economists who study growth and progress don’t think this is a coincidence. Innovations and discoveries are made by people. In a world with fewer people in it, the loss of so much human potential may threaten humanity’s continued path toward better lives.

That remains to be seen. The most obvious objection is taken up in a more recent post (Jan. 12) at Crooked Timber by John Quiggin, Mute inglorious Miltons. After a brief quote from Gray’s “Elegy Written in a Country Churchyard,” Quiggin notes:

Billions of people alive today (the majority of whom are women) [...] with their potential unrealised through lack of access to education and resources to express themselves. Rather than adding to their numbers, or diverting yet more resources away from them, we ought to be focusing on making a world where everyone has a chance to be a great poet or inventor.

I’m deeply sympathetic to that argument. I would also note that we are moving into a future where new and as yet unimagined or just-barely imagined computational tools (so-called AI) will augment and extend human creativity. For those reasons alone it is not at all obvious to me that we can justify an ever-larger population by pointing out that we need more people to make more “inventions and discoveries.” Frankly, this kind of argument strikes me as a rationalization for the Ponzi scheme economic structure that engels pointed out.

Let us return to Spears:

Sustained below-replacement fertility will mean tens of billions of lives not lived over the next few centuries — many lives that could have been wonderful for the people who would have lived them and by your standards, too.

That strikes me as typical long-termist thinking which, in this instance, I think is bonkers. I do not think that the universe is keeping tabs on how much ‘goodness’ there is in the world and will, at some future date, be raising the ethical action (EA) scores of those who have contributed to a long-term term increase in goodness by encouraging population growth in the present.

Let’s continue with Spears:

Perhaps that loss doesn’t trouble you. It would be tempting to welcome depopulation as a boon to the environment. But the pace of depopulation will be too slow for our most pressing problems. It will not replace the need for urgent action on climate, land use, biodiversity, pollution and other environmental challenges. If the population hits around 10 billion people in the 2080s and then begins to decline, it might still exceed today’s eight billion after 2100. Population decline would come quickly, measured in generations, and yet arrive far too slowly to be more than a sideshow in the effort to save the planet. Work to decarbonize our economies and reform our land use and food systems must accelerate in this decade and the next, not start in the next century.

This isn’t a call to immediately remake our societies and economies in the service of birthrates. It’s a call to start conversations now, so that our response to low birthrates is a decision that is made with the best ideas from all of us. Kicking the can down the road will make choices more difficult for future generations. The economics and politics of a society in which the old outnumber the young will make it even harder to choose policies that support children.

If we wait, the less inclusive, less compassionate, less calm elements within our society and many societies worldwide may someday call depopulation a crisis and exploit it to suit their agendas — of inequality, nationalism, exclusion or control.

By all means, let’s start those conversations.

Why are birthrates low?

The main reason that birthrates are low is simple: People today want smaller families than people did in the past. That’s true in different cultures and economies around the world. It’s what both women and men report in surveys.

Humanity is building a better, freer world with more opportunities for everyone, especially for women. That progress deserves everyone’s greatest celebration — and everyone’s continued efforts. That progress also means that, for many of us, the desire to build a family can clash with other important goals, including having a career, pursuing projects and maintaining relationships. No society has solved this yet. These tradeoffs bite deep for parents everywhere. For some parents, that means struggle. For others, that means smaller families than they hoped for. And for too many, it means both.

Yes, celebrate by all means. And I agree that we do have a problem of conflicting desires. As far as I know Spears is correct that no society has yet solved that problem.

But that problem will exist regardless of how large the world’s population grows. The problem, as described, has to do with allocation of time, effort, and resources at the level of individuals and families. Adopting policies that encourge the increase of population beyond 10 billion will do nothing to alleviate the conflict that individuals and families feel about the allocation of their attention and other resources. On that score, such policies will only increase the number of people who feel this clash of desires. How does one enter that clash into the utilitarian calculus of goodness?