Animals have "r/k selection": https://en.wikipedia.org/wiki/R/K_selection_theory ; some have huge numbers of offspring (e.g. spiders, most fish), some carefully nurture a single egg per year. Humans are already at the smaller number of offspring compared to the rest of the animal kingdom, but what I think is happening is that social pressure has simply pushed the tradeoff hard into "quality".

That is, the message is "unless you can give your children a perfect life, you shouldn't bother".

Certainly the main victory against birthrate worldwide has been the long process of eradicating teen pregnancy.

> Easy access to contraceptives probably makes a significant difference too

This is so basic as to be an axiom of the whole thing. The politics of going back to forced childrearing through suppression of healthcare are horrific, but some of the US is pushing for that.

I'm not going to find sources right now, but from my understanding the research shows that the greatest impact on number of children is education of girls. Once women have more options, staying home their whole life popping out babies seems less desirable.

There will no doubt be a push by some of the most conservative idiots to stop educating girls.

Flash news - todays people have higher standards and expectations of living than your grandma and grandpa. In particular - most people want college education for their kids. College education comes with tens of thousands in expenses and people are like "how am I gonna put 2 kids in college? I think I will have 1"

Another flash news for people who haven't had kids in daycare for a while - pricing for daycare means that for the first kid the mom could work and come ahead money wise. Second kid is about neutral (depending on location and salary, in some cases the mom comes ahead money wise, in other case she does not). Daycare pricing made us decide to have 1 kid - if we had 2 kids in daycare my wife would have been better off staying at home (which we could not afford and she did not want to do anyway).

Access to contraceptives make a significant difference as well.

In my opinion, it mostly comes down to contraception and changing lifestyle choices. Most child-free people I know simply prefer not to have kids.

That said, I wouldn't be surprised if, within a few decades, the dominant concern swings back toward "overpopulation" as major advances significantly slow or reverse aging.

> my grandmother had 17 siblings

Another anecdote. Nobody in my extended family has more than 3 kids. My grandmothers from both sides had more. But the trend is pretty clear. Fewer kids for the modern generation. Regardless of the level of education and income. In fact, the lower education/income ones in my extended family have fewer kids.

I can't agree with you enough. I am so sick and tired of the cost of living argument. Back in the 1800s people were living in tiny cramped places and having 5-6 kids while barely able to afford necessities.

>I think the "cost of living" explanation for low birthrates is just wrong

If you're demanding it be all-or-nothing, then sure it is "wrong". It obviously isn't the only reason. As countries get richer, people have fewer kids.

Is it a factor? Of course it is. Children are incredibly expensive if you subscribe to modern norms and expectations. There are many, many, many people who want kids but can't afford it, and if they do have a kid it's prohibitive having more than 1. Two is basically financial suicide for many. And to be clear, I have four children which is a luxury of being in a financially rewarding career at the right time, but even still it was unbelievably tough making it happen.

"anecdote: my grandmother had 17 siblings"

Standards change. You understand that, right? If you're middle class in 2026, the expectations around having and raising a child are very, very different from someone sixty years ago. People generally aren't keen on having six kids sharing a room these days. Even bunkbeds are considered poor by many. Now since both parents will have to work, account for childcare, massive vehicles, education savings, and so on.

Contraceptives will be harder to get. Project 2025 is also about stopping the "senseless use of birth control pills".