I think we need to take into account naturally occurring negative reinforcement feedback loops. For instance, you write that “Amish-like insular fertile subcultures are known for living in small rural pacifist egalitarian fundamentalist-religious isolated communities”.

But insular rural subcultures don’t scale very well. You can’t support a population of 300 million amish in the US if they’re all living in small tech rural communities. So that means either fertility will decline due to carrying capacity limits (e.g. lack of affordable living space), or the Amish will have to adapt to urban living, which puts them into contact with mainstream culture, which inevitably introduces fertility stagnation...

So it seems like there are strong negative reinforcements which will prevent such subcultures from scaling up and dominating the world demographics. I’d be curious to hear your thoughts on this.

Expand full comment

1: Nuclear.

2: Create technology to reduce the cost of motherhood, e.g. uterine replicators, robonannies, LLM tutors...

Expand full comment

I don't think the right outside some very small corners of podcasting universe is concerned about fertility. Maybe it'll catch on as an issue, but it's not anywhere near where global warming is to the left. Since it hasn't been politicized it's unclear we can't actually solve it. There's no ozone hole, right?

Expand full comment

Amish live under protection of US government. They won't survive without it if they don't change their culture.

Expand full comment

Could gametogenesis and embryo selection derived from the former technique kind of attenuate the catastrophic scenario? We could have babies with way higher IQs, way more productive adults, more scientists, etc. Even with a smaller population because its quality would be substantially higher.

Expand full comment

A world dominated by Amish or other tech-rejecting society is quite literally worse than "stagnating" big economy with shrinking population. They will never outcompete precisely due to their insularity and tech-rejection, it will be a 300/Cortez scenario - small but technologically advanced group will beat big but technologically retarded one 10 times out of 10. (Christians are not a good counterexample - they were coopted, and most of their original communist/commune-ist ideals literally destroyed from with in.)

Expand full comment

This seems unnecessary, after all the extent to which these groups are abnormal will radically decrease thanks to the relative fertility issues. The Mormons aren't the Amish and I'd just expect groups like them to become larger *and* for the fertility inside those groups to increase as well thanks to selection for higher fertility subgroups.

Also, I think you underestimate the effects of genuine evolutionary selection. Until recently there was very little pressure to select for genes that favored having a large family as opposed to ones that merely selected for high sexual interest. This has only changed extremely recently and it places a really strong selective pressure on those genes.

As long as worldwide culture remains as it is - not hostile to but merely not encouraging of large families - I'd expect these two factors to be more than sufficient in the long term.

Expand full comment

Wrote this on MR, cross-posting it here:

I have discussed this online and in person with Robin Hanson, who is one of the most brilliant and future-oriented people I will ever meet.

I think Hanson is right about a great deal of his analysis. Where we part ways is his view of the inevitability of decline and how late in the game we are.

I think it is far earlier in the game than he does. In short, we aren't even yet trying to solve this problem -- not in America anyway, which is the country that matters most for global culture. No political leader in the West ever even mentions it. Some Eastern European and East Asian leaders are worried, but their cultures are completely enveloped in American culture, so they can't develop a separate pro-natalist culture when America is not yet concerned at all.

I have a lot of related points to make:

(1) To compare this to global warming is to show how early in the game it really is. Political leaders in America have uttered the words 'global warming' probably tens of millions of times. I can count on zero hands the number of times political leaders in America have fretted about the low fertility crisis.

(2) Another way to gauge the level of official concern, think about the scope of the military budget as compared to the scope of funds to address low fertility. In America, the ratio is perhaps 1000 to 1 in favor of the military, even though national greatness surely depends much more on fertility in the long run.

(3) We **can** have a boost to fertility that is broad based, across all parts of society. That is what the Baby Boom was. It was a cultural shift worldwide that saw birth rates soar from below replacement across Europe and America to far above replacement all over the world. (In the 1930s, replacement fertility was above 2.1 due to higher child mortality).

Here is a great thread on the cultural shift that gave us the Baby Boom.


(4) Comparisons to the ancient world are somewhat inapt. Ancient Rome needed a TFR of 6 births per woman just to reach replacement fertility because infant mortality was so high. That is a lot to ask! We would only need to reach the low 2's, a much easier bar.

(5) The potential for having children is very high. Women who want to have a bunch of children and start in their twenties can have ten or more surviving into adulthood pretty straightforwardly. Almost nobody even thinks like that these days. Rose Kennedy and Queen Victoria each were upper-elites who had nine children at a time when having children was en vogue in their countries. It just isn't the fashion at this moment.

I am in full agreement with Robin Hanson on how dire this problem is. Most people don't realize we are facing near-certain economic declines a-la Japan due to demographic shortfalls already baked in. (There is a 25-year lag from birth to productive citizen so low fertility now is guaranteed to give us big problems down the pike.) It has the potential to well-and-truly collapse civilization. But where I part company with Dr. Hanson is in the inevitability of it. I think most people only even learned this was a problem within the last two or three years. If people just deeply internalize that they **should** have more kids, that mental shift alone might raise fertility rates enough to solve the problem. Of all the developed nations, only in Israel is the public broadly afraid of the consequences of not having enough children and they have responded rationally.

MoreBirths on Twitter/X is a great follow to learn about ways we can turn this around whenever we get serious about it. So far, we aren't remotely serious about it.

Here is good thread on possible solutions. A lot of it is straightforward, but almost nobody is comprehensively thinking about how to solve this yet.


Expand full comment

Meh. Fertility decline is overstated. 8 billion is enough.

Expand full comment

I feel like this issue would benefit from a good mathematical model. Assume that there is some pressure towards having the same number of children as your friends do and that society is made up of a range of communities from the relatively insular to some mainstream pool (ie affecting what fraction of your friends you choose from within that group).

That model explains why the more insular a group is the easier it is to have a highly divergent birth rate. But I also suspect that model will also not allow much long term depression of birth rates except in the most homogeneous cultures because once you run into issues you quickly have a correcting force that actually pushes up the birth rates of both subgroups and the population at large.

It wouldn't be hard to code this up and have some knobs that adjust the rate at which people leave subcultures to see where it runs into long term fertility issues but I expect it will take quite a high degree of homogeneity to allow for more than a short term decrease or a very very large rate at which people leave the subgroup.

Expand full comment

Most folks i know worry about price of food, energy, domestic insurance, and other vitals like taxes. Stuff right here in front of your nose. Shiny stuff like climate change or fertility are far away. They dont care. They care about today and next week. They worry about money. They worry about crap healthcare or education. Fertility, what about emptying my bins or getting post more than twice a week. Lala land versus cold hard reality of those living week to week.

Expand full comment

I do detect some forced tech aculteration (aculteration should be something that forms naturally, and not tech forced by the way) here, and also by example of the amish who never did no one any harm by being themselves, a almost relentlessness for their culture? To be cultural diverse is exactly what makes it beautiful and what makes us belong in a certain group (smaller than the plastic tech group for sure, but never the less) with most often (christian) religious undertones.

Expand full comment

Respecting the autonomy and values of future overlords while finding ways to present information and technology that align with our goals is a delicate balance.

Expand full comment

Spree killing seems like the thing the left and right both like to get worked up about and push opposing ineffectual prescriptions for.

Expand full comment

Fertility decline is what people on the right cry most about? That's not my impression unless you mean things like abortion and immigration can be lumped together as really being about fertility, but that seems like a stretch.

Expand full comment

This post is so far removed from reality that it is difficult to know for sure that it isn't satire.

In 1355, the Ming emperor decided that cotton was a strategic good, and he instructed the people in a particular region to grow it. So they did.

In 1959, a different Chinese government decided that backyard steel furnaces were a strategic necessity, and he instructed the people to build them. So they did.

If a Chinese government five or twenty-five years from now decides that falling population poses a strategic threat, it will simply instruct the Chinese people to have more babies. And they will.

Because China. End of story.

Expand full comment