I have a different pet explanation from the other replies here, and I honestly don't get why it's not talked about more.

Basically, our economic reality and expectations have come into conflict with biology and human lifespan.

If you want a secured dignified life and basic prerequisites to starting a family, every year that takes a little longer. And these days, almost everyone wants that dignified middle class life before they start a family.

A degree, an advanced degree, a good enough job, sufficient housing, a little fun to boot. Not until 25, 28, 30, 33, 35.

But we're supposed to have children in our early 20s. That's when we're strong and energetic enough, with good backs, and grand parents fit and willing to pitch in.

When we finally feel ready in our mid 30s, we find that time has conspired against us. Our parents are far away and often ailing and demanding care and attention. We have less energy and more stress and dread the lost sleep. We have the wisdom and worldliness to know just how hard this is going to be. And once we've metabolised all those things, that's when we realize that conception is no longer a question of a great night out and a few drinks. How many kids will be born at the end of that gauntlet? We're finding out right now.

There are so many factors. I think the biggest one is that the developed world looked at women and said "hey, they are just as smart and capable as men and if they work at companies we have 2x the workers" which is obviously true but what it leads to is a DINK society - and it locks you in. It is just much, much harder to raise children when both parents work and they don't live near their parents and other familial support. Add that into your observation that the world is more fun and selfish and it multiplies.

A lot of the decrease is also correlated with access to birth control which drastically reduced accidental pregnancies which were a decent amount of the fertility rate. Then we attacked teenage pregnancy with a vengeance. In 1957 it was 96/100k teen women had babies, 62/100k in 1991 and now down to the current rate of 11/100k. The postponement of births expands the time between generations which compounds the problem. An 18 yr old could have a baby that has a baby at 18 before a 36+ year old mom has their first child.

All this leads to exponential decay of humanity. In the near term we don't have to worry about extinction but we do have to worry about the pyramid schemes we have to support non-workers (like social security). This will all play out much sooner in Asia where the TFRs can be half of the US/EU. Imagine due to China's one child policy a young working person will soon have to support 2 parents and 4 grandparents somehow. There will be some kind of reckoning and some of the speculation around what it will look like is quite grim.

There's some evidence that mobile phone access is one of the biggest drivers in this. This talks about teen fertility but I'd imagine it's similar in other age categories as well.

https://homepages.uc.edu/~moscoshn/Personal_webpage/papers/S...

i put off children because it takes longer to establish a foothold. not because i loved to travel or eat out necessarily, or felt i needed to prioritize hedonistic activities over building a family. but, during that time of getting my degree, figuring out my career, get some savings, etc.. those were the things to fill up time with.

i'd trade it all for having kids younger though. it's just that they would have come at a time that any kind of grip on my future was still tenuous.

I agree a lot with your hypothesis. Most people in my demographic (mid 30s American) that aren't having kids are choosing not to primarily because they don't want to really interfere with their current lifestyle. Money seems to be a part of it, but secondary to the high opportunity cost of children.

There are also social effects. When half your friends have kids and half don't, you can compare the lives of each and decide which you want to live. You won't be as isolated now if you choose to have kids... in fact the trend seems to be more that having children is the isolating choice.

Part of it is activities but I think the majority is that if you want a good living, you have to work in cities. But cities are very expensive to live in due to unaffordable housing. Not to mention people don’t feel secured when employment is so unstable. People don’t want to take the risk to have kids if they can’t afford a permanent home and stable employment.

Is it hedonism if a child-free adult gets fulfillment out of nurturing and caring for others, mentoring, caring for themselves and their community?

That's like, the complete opposite of the hedonistic young couple not using protection and accidentally getting pregnant.

I grew up blue collar and pitched in with my father's work from a very young age. As a child I was able to balance out the time and expense of raising me by contributing back to the household. I have children and they just cannot contribute to my white collar job. They can participate in some chores, but they are essentially a massive money pit. Daycare is more than my mortgage. Public school gets out at like 2:30. It's just so exhausting sometimes.

This seems like the obvious explanation, though I think your use of the term "hedonism" is distracting. People are inherently selfish (how could any entity not be "self"-ish to some degree?). The bottom line is that we do things because we want to. Even selfless activities feel good. That's fine, honestly. But having children is not intrinsically non-hedonistic. It's just one of many self-fulfilling activities we choose from.

I'm the same as you. I, too, think it's just opportunity cost. Even a superficial model will show some effect as median income rises https://wiki.roshangeorge.dev/w/Blog/2025-02-14/Fertility_Ra...

For the first time ever people can finally choose not to have kids.

Is it really any surprise people would opt out?

Go spend a day with kids and you'll see why people would rather not deal with the mess.

Especially women who actually end up doing the majority of the work.

Add to that the extinction level pressures like climate change and the absolute lack of any benefit whatsoever in being a parent, who is crazy enough to willingly sign up for this if you actually put any thought into it instead of just "that's the way things are though!!!"

Every day I praise the man who did my vasectomy lol

you are right IN:

a) there is a lot of fun to do "outside there"

but you are MASSIVLY wrong in:

b) children are meaningful, they give you more than the consumption you can have - rent one month into brothel and you will see! ;-)

(source: father of twins, and nearly bankrupt regardless of my tech-job, nontheless my kids me more than our usual career-shit)

you are right IN:

a) there is a lot of fun to do "outside there"

but you are MASSIVLY wrong in:

b) children are meaningful, they give you more than the consumption you can have - rent one month into brothel and you will see! ;-)

I would argue it is due to nuclearisation of families, that has always accompanied industrialisation. See my other comment on this post https://news.ycombinator.com/item?id=48416228

I think it's not industrialization but urbanization.

The links you posted seem to say that government fertility support policies actually do have a big effect.

I know the "bring them into this world" thing is overdone, but a big part of me feels it to my core.

I haven't seen a firefly in a couple years. If I had a child today, describing this bug to a child would be almost mythical.

How many things that we've taken for granted will a child born today never get to experience? Not shallow things like iPods, but genuine miracles of nature we're wiping out at an accelerating pace. I can't in good conscious bring a child into a world that so many are focused on absolutely destroying.

It's my protest to allow the pyramid of consumption to collapse. I will not bring a just another customer into the world. I won't bring a child here just so they can be a pawn to try to recover from poor planning.

We as humans need this population collapse. We need to learn how to organize society on long-term sustainability, not a pyramid scheme.

Every time I see this discussion, it's always framed like a call to action, that we need new children to bail out the sinking boat and keep it floating for another generation or two.

One could make the point this is less about industrialization causing a change in behavior, and more chemical pollution destroying fertility. Of which we have plenty of concrete evidence.

>My hypothesis is that as societies industrialize, they afford their population more and more activities that are simply more fun and rewarding than having children.

But this is by and large not true. I've traveled, eaten at expensive restaurants, enjoyed a child free existence into my mid thirties and having kids is a blast[*]

My wife was adamantly against having kids when we got together in our twenties, and she changed her mind in her late thirties; she now says that was the best thing that has happened to her.

Finally, there are many studies showing that people lead happier lives when they focus on someone else, have a higher purpose beyond just hedonism or living selfishly.

[*] - I have a supportive partner who collaborates with me so we both get time away and time off from the occasional drudgery or exhaustion of parenting. I still get time to work out, see friends, have time with my wife, all of that. If I couldn't afford the occasional babysitter and had a partner who was absent most of the time, it would be a lot harder!

India has barely industrialized though.

While this is generally true, the first derivative of the baby bust curve is far from uniform across the planet. Indian fertility drop has been very sharp and who knows where it will end.

[*] All parts of the Israeli population have high birth rates, even the secular Jews. I find it misleading to single out Orthodox Jews as the main contributor. You don't do that to Evangelical Christians or Mormons, or some other groups in US.

I don't think the religion is the driver here.

Except in [0] the birth rate is relatively flat between 1950-1970 and then suddenly starts a rapid reduction. Developed countries have already been industrialized for 100 years by that point. The modern work day and access to many modern fun and rewarding activitys have been available for literal decades. Mass urbanization already occurred. Many of the modern household appliances have been in use for decades. Antibiotics, vaccines, and childhood mortality had already been dramatically reduced to within the vicinity of modern norms. In developed countrys female workforce participation, education, and political activity were material with no clear fundamental shift in those metrics in the 1960s-1970s.

But you know what did occur in the 1960s-1970s? The invention and popularization of the birth control pill. Here is the US birth rate [1]. Rising from 1950-1960 then a sudden and precipitous drop in the 1960s until stabilization in the 1970-now range. This coincides with the global drop in fertility rate. How about Germany [2]? Growth from 1950 to late 1960s then a sudden drop until stabilization in the mid 1970s. France [3]? Flat and high until mid-1960s then a sudden drop until stabilization in 1980. UK [4]? Growth from 1950 to mid 1960s then a sudden drop until stabilization mid 1970s. Australia [5]? Growth until 1960 then drop until stabilization in 1980.

Every single developed country in the world is flat to growing and then sees a sudden and rapid decline in birth rate just a few years after mass availability of the birth control pill until stabilization around the time that the pre-birth control cohort ages past reproductive years. The birth control pill is so new that the reproductive cohort that lived prior to its invention is still alive.

My hypothesis is that fertility is just a function of access to cheap, effective contraceptives. The fertility rates we see today are the natural rates when pregnancy is a choice.

[1] https://www.macrotrends.net/global-metrics/countries/usa/uni...

[2] https://www.macrotrends.net/global-metrics/countries/deu/ger...

[3] https://www.macrotrends.net/global-metrics/countries/fra/fra...

[4] https://www.macrotrends.net/global-metrics/countries/gbr/uni...

[5] https://www.macrotrends.net/global-metrics/countries/aus/aus...

Which is not a bad thing. We have limited resources. It’s not a bad thing to slow down. Even if we’re having fewer babies, we’re far from endangered, despite some (dishonest, IMO) narratives.

I don’t necessarily disagree with your overall point, but for some reason at least in US society you’re no longer allowed to broadly talk having kids like you used to be able to. Let me break that norm for a second.

So, are other activities more fun than child rearing? Often, yeah. Definitely less stressful. Rewarding? Not in a million goddamned years. Nothing, absolutely nothing, compares to when your kid first walks, talks, tackles a problem they had a hard time doing before, or tells you that they love spending time with you completely unprompted.

For what it’s worth, I personally think a good portion of the birth rate dropping is environmental. Maybe it’s plastics, pfas, or something else nobody is looking at. Some people still have an urge to have kids, completely separate from the urge to have sex. I don’t think it’s a coincidence that testosterone and sperm counts have been dropping among humans and dogs, and that the deliberately child free people I know all veer on the (forgive the derisive slang term, but I don’t know how else to get the point across) “soyboy” type of person - both male and female.

That potential pollution aspect also explains this happening to industrial societies.