Why increase fertility when you can just allow more immigration?

My YouTube comments give me great post ideas. This time, on a video about fertility, frequent favorite sparring partner FishareFriendsNotFood972 asked, “Do we want to increase the fertility rate, though? The fertility rate is fine, globally, and I don't see an issue with increasing immigration and naturalization if we ever start having real struggles in the US.”

My response was basically that this was a question worth exploring in a separate blog post.

This is that blog post.

TL;DR:

1. Low fertility hurts economic growth, which is bad for a bunch of reasons.

2. Global fertility is on track to eventually peak.

3. Mass immigration also has risks.

Whether we should increase the fertility rate is a difficult question for a few reasons. First, it’s not at all clear that we can. Second, most of the ideas proffered by the right either are unlikely to work based on current evidence, the cure is worse than the disease, or both.

That said, it’s lazy and unhelpful to look at such a problem and then decide it’s not really a problem, or that it’s a problem that’s actually easy to solve. First I’m going to lay out why a declining population is a problem for a country. Then I’m going to explain why I changed my mind about whether simply importing immigrants from growing countries to shrinking countries can efficiently solve these problems long-term. Lastly, I’m going to talk about how to actually solve the fertility crisis.

Fertility and economic growth

A shrinking population is likely to slow a country’s economic growth.

“Young people are the generators of ideas, innovation, entrepreneurship and labour productivity,” writes Alice Evans. “Ageing populations thus risk undermining economic dynamism and straining state capacity.”

Samantha Hancox-Li pointed to South Korea to illustrate how and why a large, aging population and a much smaller working-age population kills economic growth.

Why do we care about growth?

Economic growth is worth worrying about for all kinds of reasons. It’s strongly positively correlated with pretty nearly every measurable thing you’d want and negatively associated with nearly every measurable outcome you’d want to avoid.

Economic growth is associated with lower levels of absolute poverty. People in fast growing economies tend to feel more optimistic about the future. Growth is associated with

life satisfaction. As economies grow, their infant mortality rates decline. People become happier, less violent, more free. Kids get more education. Leisure time increases. People make more art. And average lives get longer and healthier.

Degrowth caused by population declines in particular may exacerbate inequality.

There are other downsides to population degrowth as well, including declining economic prospects for younger generations and decreased military capacity relative to more populous and bellicose neighbors.

“Advocates of degrowth have pointed out the manifest unsustainability of such intergenerational pyramid schemes, but their implosion will probably not be peaceful,” Gideon Lewis-Kraus wrote for the New Yorker.

So those are the good arguments, in my opinion, for caring about fertility. Maybe it’s not a bad thing in and of itself, but it is associated with outcomes – like violence, misery, and infant mortality – that most reasonable people should want to avoid.

Global fertility

I used to dismiss these concerns as white nationalism/white genocide scaremongering. Why else not just increase immigration?

I really liked what

Darby Saxbe

wrote about immigration here:

The best way to boost births (that no one is talking about)

Unfortunately, immigration alone cannot solve declining population trends long-term.

First, mass immigration is a short-term fix. As far as I can tell, immigrants tend to adopt native fertility patterns within a generation or two.

Second, eventually, we will run out of immigrants. As it turns out, the global fertility rate is not fine. Yes, technically, the global population is still growing.

But that won’t continue indefinitely. At some point, rich countries will literally run out of humans to import.

Right now, two-thirds of the world live in countries whose fertility rates are below replacement. The UN keeps moving the date they expect the world population to peak, currently in the 2080s, closer as fertility falls faster than predicted. Experts predict 97% of the world’s countries to fall below replacement by 2100.

So not only will we run out of people eventually, but in the meantime mass immigration poses risks to recipient countries.

Mass immigration risks

Look, I love immigration and hate nationalism. Fuck that blood-and-soil bullshit. Only losers make where they happened to be born a foundational part of their personal pride and self-conception above and beyond their personal talents, accomplishments, and contributions.

Immigration has always been and continues to be a huge net-positive for the US.

It is not, however, an unalloyed good. And the reason isn’t the immigrants, but the natives. Especially the loseryest ones.

“Mass immigration of unskilled labor into the United States is deeply unpopular,” wrote Freddie deBoer. Evidence indicates that mass migration was a huge factor in the last election up and down the ballot, especially among working-class voters.

“Trump really did win the two most essential arguments of the 2024 election, on inflation and immigration,” Ed Kilgore wrote in 2025. “Solid majorities in multiple polls support (in theory, at least) the mass deportation of undocumented immigrants.”

The same people who say “just increase immigration” because they’re (rightly) concerned about women’s rights probably should care that mass immigration increases support for right-wing extremist candidates and policies.

When you combine mass immigration with the fact that record numbers of women are saying no to dating, marrying, or procreating with low-status men these days, “If this trend continues, every election will be an incel election,” Gideon Lewis-Kraus wrote for the New Yorker.

There’s one more problem associated with falling fertility that immigration can’t fix.

Immigration won’t solve the problem that people say, in surveys, that they want to have more kids than they end up having.

What people want

I think this question is worth digging into a little bit. The following is a bit of a soapbox moment for me, and isn’t necessary for the overall point of the piece. So feel free to skim or skip until the line that just says “Anyway.”

One demographer at the University of Colorado Boulder named Leslie Root has qualms about this data. As she pointed out to Vox, it often lack nuance. Polls rarely consider how desires change over time. For example, YMRI pointed to a poll of young men in which two-thirds agreed that having children was important to them, but just 40% agreed that they were ready to be fathers. So which is the “want?” People also tend to answer differently in front of their partners and other family members.

Another wrinkle in the “people want more kids than they have” is that women in countries where women want to have more children tend to have more children. In the US, women of childbearing age said they wanted 2.1 children in a 2023 survey. Which is about how many we have.

The bigger problem with this kind of polling (imo) is that asking people how many kids they want is like asking people how often they’d like to work out (or how much they’d like to weigh or how much money they’d like to make). It’s pointless and irrelevant. The question presupposes a world without costs, in which case I’d like to work out every day, weigh 105 lbs, and make a bazillion dollars a second.

In the real world, I work out as often, weigh as much, and make as much money as I want to considering the tradeoffs actually involved. I also have the number of kids I want, based on what I expect parenthood to actually be like in reality for me.

In Family Unfriendly, author

Tim Carney

cites the WSJ on how women end up having one fewer kid, on average, by their early 30s than they’d said they wanted in their 20s. That’s like polling people at the start of the year and asking them how many times they’d like to order in versus cook dinner and then taking the fact that at the end of the year they’d actually ordered in a lot more than they’d said they wanted to as evidence that they really wanted to cook.

It’s easy to say, “Well if I had a home gym I’d work out every day.” For the same reason, it’s easy to say “Well, if having kids cost less money, I’d have some.” I’ve thought about having kids in the past and thought, “With what money?” I could believe a lack of money prevented me from having kids because what, except more money, would prove me wrong?

But the reality is that people have kids they can’t afford every day. Just like people without home gyms work out every day. I’d really wanted to have kids, I would have had them. I’ve bought plenty of shit I couldn’t afford. Saying “I had fewer kids than I wanted to” is like saying “I spent less time volunteering than I wanted to.”

Having actually done a thing is the only non-falsifiable proof that you actually ever wanted to make the tradeoffs required to do it in the real world.

If you only want something in a world in which it’s easier to get means you don’t want it in the world that exists.

Anyway.

So, I think I’ve made a good case for caring about falling fertility and being interested in exploring solutions that can work better and for longer than immigration and come with fewer unintended consequences.

Unfortunately, we don’t know how to boost fertility. We haven’t even figured out why it’s going down.

We do know that anyone saying “It’s just costs,” for example, is wrong. We know this because there are places and times where costs and fertility do not correlate. Same for income, laws, labor markets, parenting norms, and every other often-posited reason. No single cause we’ve looked into can fully explain fertility in every place and time. Which means, most likely, that it’s multi-causal. The closest thing we’ve found to a universal is that when you give women access to contraception, fertility tends to decrease. But here again, not always and certainly not always by the same amount.

One interesting correlation we’ve found is that fertility tends to correlate with “meaning” broadly, and religion in particular.

“The only overarching explanation for the global fertility decline is that once childbearing is no longer seen as something special—as an obligation to God, to one’s ancestors, or to the future—people will do less of it,” Gideon Lewis-Kraus wrote for the New Yorker.

I don’t buy that secularization is necessarily causal to fertility declines. But I do buy that there’s a connection between meaning, belonging, well-being, and fertility. Rather than seeing meaning as a solution to falling fertility, however, I actually see fertility as a barometer for meaning, belonging, well-being – the things I care about for their own sake.

“Objectively, the world is going to hell,” my friend Brink Lindsey wrote. “There's a lot of problems with kids these days. So I'm always wondering, is it me or is it really the world? To me, the slam dunk argument that things really have taken a wrong turn, that our social system really is making us spiritually poor while it's still making us materially richer, is what's happened to fertility. This is the ultimate existential test for a society or a culture, even more basic than the test of war. A culture that can't reproduce itself isn't sustainable, period. And modern urban consumerist capitalism isn't reproducing itself. Quite simply it's on the path to extinction.”

I think I care less about the problems falling fertility causes and more about the crises it illuminates.

In terms of what to do about falling fertility, we should dismiss solutions that harm existing people out-of-hand.

(Weird how it’s always women and minorities that need to suffer for the sake of theoretical people.)

You don’t definitely hurt existing people for something that might lead to more theoretical people. And “definitely will work” is an impossible bar to clear. Again, we have no idea how to boost fertility. Nothing that’s been tried has worked. Subsidies have had limited impact, but to get from very low fertility to sustained replacement-level breeding experts estimate that governments would need to spend six figures per child.

“Pro-natalism” should be explicitly feminist (and pro-immigrant, pro-queer, pro-Black, pro-people with disability, etc.). The fact is, we don’t actually need to choose between boosting fertility and helping existing people. There are lots of policy changes and changes to cultural norms that could, at least theoretically, do both.

So I support efforts to at least look into ways to increase fertility if and when they benefit existing people for three reasons.

First, because simply allowing more immigration isn’t going to solve the problem forever and comes with its own risks and downsides. Second, because it might help us find novel solutions to other existing and future problems.

Third, and most importantly, because “why aren’t we having kids and what would make us do it again” is a question I find genuinely interesting.