Fascinating topic. I personally suspect that it has more to do with attitude and life style priorities rather than economics. But I remember reading a very recent article in the Economist that argued that birth rates declined mostly in low income families, which would contradict that.

> Underpinning these policies is an assumption that poorer women are more likely to respond to incentives to have more children. Indeed, their fertility rates do seem more elastic than those of professional women. Whereas the fertility rates of older, college-educated women have remained fairly steady over the past six decades, most of the collapse in fertility in America and Britain since 1980 stems from younger and poorer women having fewer children, particularly from unplanned pregnancies.

https://www.economist.com/leaders/2025/06/19/why-magas-pro-n...

Just like with many of these topics, most sources seem to contradict each other.

Because for most rich countries this graph applies:

https://www.reddit.com/r/dataisbeautiful/comments/e1jrvw/oc_...

Part of the reason is probably that nearly all high income countries have terrible housing policies that make it impossible for ordinary people to have stable housing until their late 30s/early 40s.

TIL - fertility is used interchangably with birth rate in demographic studies. What I think of as fertility - the ability to have offspring, in a purely biological sense - is apparently termed 'fecundity'.

This is only mentioned briefly in the 'infertility' subsection, and then only attributed to age, with mention of IVF as a mitigating factor.

However, there is evidence that, due to a variety of factors, there is a steady but persistent decline in sperm count globally, and that this had a sizable impact on birth rates/fertility.

https://rbej.biomedcentral.com/articles/10.1186/s12958-023-0... "Infertility affects one in every six couples in developed countries, and approximately 50% is of male origin."

I think at this point the better question is: why in the past fertility was so high? and I think the reasons were mainly that people _relied_ on their children to grow up and take over the farm and take care of their parents. They were also mortally bored and children are fun. They had them for selfish reasons.

But nowadays? why would you have a child? for a middle class+ family in a developed country, having a child is a 6 figures expense over their lifetime, limits your career, holidays, etc. From a selfish point of view, it doesn't make a lot of sense.

I don't think it's the only explanation but children are, individually, optional so you can, for selfish reasons, do it or not.

In high income countries, you have to provide your child with higher education to have a competitive income. Because education is expensive, having more children makes it impossible to give them a good education. On top of that higher education occurs during the period that humans are the most fit. Fitness and fertility rates drop quickly after the age of 30.

Its not just high income countries. Fertility rates are similar in a huge range range of other diverse countries (Colombia, Cuba, China, Vietnam, Thailand, Turkey, Iran, etc.).

I’ve seen somewhere an uncomfortable chart which shows that fertility rate is almost perfectly inversely correlated with a single number: average years of women education. Also what’s interesting, allegedly, reducing the average woman education seems to be the only reliable way of growing diminished TFR. Please don’t kill the messenger, I’d love to be shown it’s false.

Couldn’t find any details about this on a quick skim of this paper on my phone.

Also, I think, to many people it’s becoming obvious that increasing birth rates cannot be achieved with measures that make people feel good, unfortunately. It will likely be a tough choice between bad and worse.

I am 40 and live in Germany. In my 20s I was too poor to start a family. Now I live with a woman who has no desire to go through pregnancy and become a mother. There are personal reasons for this, and I do understand them. I like children and would like to be a father. But I work full-time, as does my partner. I'm always busy after work: Riding or wrenching on my motorcycle, cycling, personal programming projects, gardening, etc. Yesterday I spent the afternoon cleaning a carburetor and pressing bearings into wheels. I spend the weekends doing sports or visiting friends. Becoming a father would be like a second full-time job.

I saw a homeless man lying on a patch of grass in a dirty sleeping bag on my way to work yesterday. The idea of bringing a child into the world and exposing it to the risk of ending up in a situation like that just makes me sad. We are currently buying a house. If I could have afforded this ten or fifteen years ago, I might have kids now. Looking back, I'd say I've had enough to do with growing up and providing for myself financially. I simply didn't have the capacity to start a family.

A friend of mine has two children. She barely has enough money and is trying to finish her university studies. Another friend is a chief surgeon and earns so well that his children are not a big financial factor for him. He is divorced from the children's mother and has another partner. Another friend is a pastor and has two children. I guess, for him it was always a matter of course to have children. He is now also divorced, so he no longer lives in the picture-book family world that he probably once dreamed of.

The other people around me are grown-up children like me, who for various reasons did not become parents. One friend of mine is a gay man. His sister is a lesbian. Both much to the annoyance of their parents, who would like to be grandparents. A couple at my office in their thirties mainly play computer games after work and have pets instead of children. One of my best friends is a woman who lives with a trans man. They are currently planning to become parents via in-vitro fertilization, which will cost a total of ~20,000 euros. The world is strange and apparently no longer properly calibrated for having children.

I am glad that there is no more social pressure pushing people into parenthood. But that has to be compensated for somehow and I don't see any socio-political willingness to tackle this. Raising children is a service to society! We cannot expect children to grow like grass in an unattended meadow. If society is not committed to guarantee healthy soil and to water the gras properly, then nothing will grow.

I’m a 35-year-old living in Berlin, and according to government statistics, I fall into the higher earners category. However, having a child here feels completely out of the question for several reasons:

1. Lack of quality healthcare –> I have statutory health insurance and pay a substantial amount for it, yet it often takes weeks to get a doctor’s appointment. I can’t imagine dealing with that level of delay and bureaucracy when a child might need immediate medical attention.

2. Housing crisis –> Finding decent housing in Berlin (or any major German city) is incredibly difficult. Even a small room in a shared apartment costs around €600–700 per month if you’re lucky enough to find one. Securing a reasonably priced apartment suitable for a family could take years.

3. Rising cost of living –> Back in 2018, €50 could cover quite a lot; today it barely pays for a single grocery trip covering just a few days. Adding a child to the equation would make it feel like living paycheck to paycheck.

Many of my friends are also postponing having kids or have decided against it entirely due to financial concerns. In addition, quite a few of my female friends don’t want to have children because of the physical toll pregnancy would take and the loss of freedom it would mean, especially when compared to their male partners. It’s simply not something they’re willing to accept.

I think there's a few components.

One is opportunity cost: You simply have more options (especially women), so having children now comes at the cost of many other potential paths whereas it used to be the default.

Housing costs: Most people want to live in a few cities per country and every desirable city I've ever heard of has an affordable housing crisis. When you can barely afford enough space for yourself, how are you going to have a room for a baby, let alone multiple.

This topic pops up on HN a lot so question to people that follow this topic: maybe someone know if there's study or argument about linking "financialization" of economy to fertility rate?

These day we take for granted that we can "save" and "grow" money through investment. Almost everyone does it more or less, through pension saving or simply investing.

Yet this hasn't always been the case for humanity. Take for example: a hunter that just scored big game (deer). He can't possibly eat it all or process it all before it rots. What does he do? He shares it to his tribes men, with the implicit agreement that when they also score, they'll share back. Investing (for future) is favors and personal agreements. In this, raising a child (to become a good hunter, a skill you can share) is included.

These days you can just invest any surplus productivity(wealth) directly in to sophisticated financial markets. The fact that availability of services purchaseable (Healthcare and elderly care) increased, have made the "just invest surplus productivity to your future savings" a better alternative than investing it to a child.

A child today is financially equivalent to a pet. Cost a lot, you can't expect (or force) much in return. It's probably not that "fun" either, for many. (especially in East Asia; so much more fun entertainment than raising a kid!)

I'm in my mid 30s soon and most (college educated) women around me usually struggle with the child or not question but the ones doing financially well often land on "eh I'll just save the money I have to spend on kids on entertainment and pension saving. It will be fine" as a option (the anxious ones freeze their eggs).

As a hypothetical thought scenario: if financial system collapsed (no more pension saving, or money simply growths with investment) would fertility rate go up?

At the basic level, even the idea of growing money to hedge for the deteriorating health at old age doesn't even make sense. In a aging population, the supply (young, working) and demand (old, requiring care) might be so flipped, whatever gain you had will evaporate in price increase. Unless immigration or other unpopular policies.

Do most people even care about this question/topic? Maybe that's part of the answer.

Culturally, fertility topic has gone through "we will never be able to feed everyone in the world" to "we should have absolute control over when/how many kids to have" and "I can't afford having kids and keep my lifestyle" and "why kids?"

Even when in economic discussions around labour availability, retirement sustainability, the topic just essentially focuses on migration policy.

Societies have moved towards a group of "empowered individuals" model, leaving behind families as a fundamental unit model

Although they gave birth to more children before the industrial revolution, most died, so the population was almost constant. If we define "birth rate" as the number of children that survive long enough to have their own children, then I believe birth rate was close to 2 back then. I believe long term the birth rate (according to my definition) always converges to 2 because anything else is not sustainable. Nothing can exponentially increase forever. Maybe the population can exponentially decrease to 0 but it's unlikely because there always be some group that will be willing to have more children for cultural or religious reasons.

The paper interestingly finds that fertility rates have fallen to historically low levels in virtually all high-income countries due to a fundamental reordering of adult priorities rather than economic factors.

The reason for the fertility decline is particularly difficult to get approach. Our rational mind wants to find a single unifying theory to explain why it is happening, but reality is likely more complex.

There isn't a single reason why people have fewer children. Each society experiences challenges, such as housing, which bear some similarities but differ a lot in practice, so it's easy to find counter-examples if you're looking for a single-factor explanation.

The article cites "changing norms", which reflects the broad social evolution happening—even rather conservative societies such as Iran or North Korea[1] have a below-replacement TFR! My pet theory is that this change is accelerated by the wide adoption of smartphones, which tend to “flatten” cultures toward global, westernized norms. It even happened in North Korea, which led the country to take radical, Orwellian measures[2].

[1] https://apnews.com/article/north-korea-kim-jong-un-birthrate...

[2] https://www.vice.com/en/article/north-koreas-smartphones-are...

Housing costs, cost of education for yourself and kids, needing to work and study longer to provide more. More women want careers longer.

Basically we compete more until everything costs more. Now we need multiple salaries because everyone we’re competing against is a highly paid couple. Rinse and repeat so everything of value is too expensive for “average people”.

Whatever the reasons are, decent countries should not fall for the temptation to launch embarrassing campaigns to rise the fertility rate. That is what totalitarian countries do. And all these campaigns seem to fail anyway. Sure, low fertility rates (if they prevails) will cause disturbances on society, but then societies must adapt.

Social media is the largest single factor in collapsing birthrates. Social media made widely accessible depictions of lifestyles that glorify wealth, travel, living carefree lives. This increased the baseline expectations people have of their own lives. Children are just an impediment to that lifestyle. Social media also massively raises the expectation of the costs of raising kids. It's no longer enough to keep them fed and clothed. A child's existence must be maxxed in terms of attention, simulation, enrichment, etc. Anything less is deemed borderline abusive.

I mostly only have anecdata, but I don't agree that the main reason are "priority changes". My son's classroom is full of parents that wanted to have two or three children but stuck with one due to already having a very hard time to achieve work–family balance with one (in fact, we are in that set). The desire to have more children is still there, but unfulfilled. There are many polls about this, see for example https://www.businessinsider.com/americans-want-more-kids-why... for the US (figure "How many kids Americans have vs. how many they think are ideal"). In my country, Spain, polls about this give very similar results, most people want 2 or even 3 kids and end up not having them.

Really rich people, on the other hand, very often have 3+ kids (as poor people do, but for different reasons). In the US, Bill Gates has 3, Bezos has 4, Zuckerberg has 3, Musk, well, I've lost count :)

The thing is that, of course, typical measures like giving some small economic aid to parents, slight improvements of a few weeks in maternity/paternity leave, etc., which are the kind of things the article focuses on, just don't move the needle. This is hardly surprising. None of those things significantly improve work-family balance. Much more radical measures would be needed, like multi-year maternal/paternal leaves with measures to guarantee that there is no or small impact on career, or a significant reduction of standard full-time working hours to, say, 30 or so a week (be it for parents or for everyone). But for all the talk about fertility being a problem that needs fixing, no country seems to be willing to do anything even remotely close to that.

Note that the measures I'm proposing are focusing on time, not money, because time is really the limiting resource for raising a child in a high-income country. Of course, with money you can buy time (daycare, caregivers, etc.) - so I'm sure things like massive building of public housing to bring down prices can also help. But it should be more efficient to focus directly on time - and more fulfilling for the parents to actually, well, have time to raise the kids themselves.

Across the developed and developing world, two factors play a huge role for REDUCED number of children per family:

1) weakening of fanatic religious regimes

2) increased women education and employment

Guess what is happening in high income countries.

One day I will understand the causes behind the fixation of HN (and other social media sites) with fertility. However I am not sure I want to.

Quote from the PDF:

> estimates suggest that individuals in their early 20s who receive access to housing credit would have twice the completed fertility relative to those who do not obtain that credit until their early 30s.

Recently Freakonomics covered this topic in a 3 part series Cradle to Grave https://freakonomics.com/podcast-tag/cradle-to-grave/

The high income countries can continue to attract an endless supply of pre-manufactured labour resources from lower income countries, so are not manufacturing it at home.

Just came here to say: I've started to read the paper (thanks to the downloadable PDF, the web version is not accessible apparently for me)

Starting at page 8 (total) or page 6 (as written in the footer), there's horrible graphs, even if you zoom in, they're all blurry and partially unreadable

I'm legit surprised we let research articles be published with poorly designed graphs using poor definition/resolution :')

#justRanting

My wild speculation is that TFR is more correlated to simply not being bored, i.e. internet pentration. Cursory LLM wank shows strong & tight correlation. Even more than income. Academically I know strongest correlation is suppose to be female education levels, but women with < middle school, or high school education in developed/OECD countries still have TFR mostly >2. VS women from developing countries, who still manage secondary still hover around 4. Maybe religion? Then you have very religious and wealthy MENA countries with access to basically cheap labour and TFR still crashing below replacement. Unless ultra religious, i.e. some jewish cohorts.

Other point is seems like pro natalist policies will only get you so far... certainly not 2.1 replacement TFR. Note every 0.1 in TFR is about 5% missing birth for stablized population. Pronatalist policies seems to icnrease TFR by 0.1-0.3, usually settle at 1.6-1.7, i.e. still down 20% net bodies. My unpleasant conclusion is positive policies not enough, need very punitive policies, i.e. high income/wealth transfer tax to really incentivize natavist replacement TFR. AKA historic incentive - if you don't have lots of kids you die poor and uncared for. All the cheap housing, free daycares, xyz subsidies is not enough. % of population will have a shit time raising their first kid and decide 1 is good enough.

Or you know... immigration, which of course going forward means disproportionately brown and black skin. Queue Family guy skin color chart meme.

Lots of hot takes here in the comments. I think that reading the paper is more informative than just reading these comments (something I am often guilty of).

My thoughts on the paper:

These are economists, not demographers or social workers. Their tools are crude for this task and they acknowledge that many times in the article.

Honestly, the abstract is well written and covers a lot of what other HNers are saying here. But I'll just quote it again anyways:

"We review existing research and conclude that period-based explanations focused on short-term changes in income or prices cannot explain the widespread decline. Instead, the evidence points to a broad reordering of adult priorities with parenthood occupying a diminished role. We refer to this phenomenon as “shifting priorities” and propose that it likely reflects a complex mix of changing norms, evolving economic opportunities and constraints, and broader social and cultural forces. We review emerging evidence on all these factors. We conclude the paper with suggestions for future research and a brief discussion of policy implications."

These policy implications are at the very end of the paper and don't really amount to much:

"That said, we do have a better understanding of the kinds of policies that could make a difference. Policies that encourage births today may simply lead to a retiming of births, resulting in a short-term increase in births but no lasting effect on population trends. To be effective at boosting completed fertility, policies must influence the decisions women make early in their reproductive lives. Interventions targeting women well into their childbearing years are less likely to have large effects, as many life choices will have already been made. This may explain why past empirical studies often fail to find large effects of pro-natalist policies. Our review of the evidence also suggests that incremental policy changes or interventions are unlikely to have sizable effects, and boosting fertility will likely require much larger changes that alter the lifetime calculation to have and raise a child or multiple children given prevailing options, constraints, and social norms. "

What I think this paper adds to the pro-natalist discussion is that, yes, this is a really hard question with no easy answers or fixes. If it is a recipe that we must follow to get a higher birthrate, then it is not stir-fry but rather lobster thermidor. The one thing that we can say is that delaying childbirth is likely to be bad for fertility. But there are little resources for how to address that.

Good paper overall and well worth the read if you are into this pro-natalist stuff. Not a lot of new data, but a great summary of the economist viewpoint of the problem and it's tenacity.

In a developed country the cost in terms of time, effort and money for a child is much higher. The modern world is simply incompatible for large families. Having more than 2 children means driving a giant car and it means a crazy amount of time and planning around after school activities in addition to needing to be up to date with their school activities.

I have 2 and I already spend most afternoons driving/picking them up from sports, If I had 3 it would literally be every day including weekends.

Because people are getting poorer. Simple, you don't need a paper.

One case: VERY much, FULLY, wanted home and family with love and emotional and financial security.

Tried. Never could. The reason:

ECONOMIC!!!!! For higher education and jobs, had to keep moving, Indiana, Maryland, Ohio, NY. The moving was EXPENSIVE in all of time, money, effort. Couldn't put down roots.

Worst part: NEVER could make money enough for a house, so always RENTED, which, long term, is a financial disaster.

Due to the financial stresses, my wife, back with her mother on her childhood farm home, killed herself.

For me, the sheriff came with several assistants and guns and dragged from my rented house all my belongings and left them on the grass. Lost my large professional library -- math, physics, computing -- piano, furniture, clothes, etc.

The shame and humiliation -- my brother's family, with 4 houses, made a place for me.

Looking back, the families that owned nice houses or even just one house, ALL were founders and owners of small-medium BUSINESSES and were NOT "employees". They were financially able to have children and DID.

Education? Wife was Valedictorian and then PBK, Summa Cum Laude, Woodrow Wilson, NSF, and Ph.D. My Ph.D., applied math and computing. These educations took time and money and made us welcome only as university research professors, and the ones I knew who had a house and children (darned few children) were all poorly paid and had other income, e.g., one was in the USAF, got a Ph.D., retired, became a professor.

Net, the US had kids from 1940 to 1960, and after that kept losing to the present where, literally, the birth rate is so low we are going extinct. Why? For good family formation, the US is a big LOSER.

Why? The US economy moved from farms to cities. The city business owners did well, but their employees didn't. So, e.g., Dad grew up in a small, country town. His father ran the general store, and his step father ran the feed and grain mill. They did well financially. Nearly everyone else in the area was a FARMER living on a FARM or working for farmers, e.g., a blacksmith, carpenter, etc. Once we visited, and I saw cows being milked and hay being loaded into the hayloft. Dad's family supported him well in college. After college, he got a job as an employee and never again did nearly so well. Wife's father? Farmer but on the side head of the local REMC (rural electric membership cooperative). Families broke up and scattered

Am still good at math and computing, so doing a startup: Hopefully from my work the children in my brother's family will have plenty of money for a good, private, college, good marriages, nice houses, close enough to keep the family together. But I don't know what they will do to be successful financially on their own.

So far it looks like in the US we need to have the population shrink by 50-75%, have people leave the big cities, have plenty of farm land per person, and live on farms, rely on the Internet and small businesses with much of the needed production automated and with the physical distribution and retailing as in Amazon.

The thought of having kids is frankly terrifying. (It was for me!) I think most responsible people wait until they are “ready.”

But, despite advances in fertility science, it can be truly challenging to have kids in your 40s.

I think it's hundreds of different reasons that eventually stem from one. Urbanization.

Summary from ChatGPT

1. Fewer people ever have kids. In every rich country the share of women who remain childless at age 45 is climbing, and it is rising at all intermediate ages as well. This is not just postponement.

2. Total family size is shrinking. Even among parents, second- and third-birth rates are trending down, so completed fertility is falling toward or below 1.5 children per woman in most of the OECD.

3. Short-run economics don’t add up. Recessions, housing booms, or pandemic shocks temporarily nudge annual births, but they neither align in timing nor in magnitude with the long-run fall.

4. Money helps, but only a little. Large cash allowances or cheap housing can raise births, yet estimates show gains of only a few hundredths of a child per woman—far from the 0.5–0.7 needed to reach replacement fertility.

5. Attitudes have flipped. Surveys across Europe, North America, and East Asia reveal a marked decline in the share of young adults who view marriage and children as central life goals; career, leisure, and personal autonomy score higher.

TL:DR; it’s culture. People don’t want kids anymore. It is not housing costs, lack of support, etc…

I think it's mainly about our modern gender roles and expectations, where both partners tend to work and earn a similar amount. With traditional gender norms, the husband was expected to be the main breadwinner, while the wife wouldn't earn much. So her subjective opportunity cost of quitting her job, staying at home and having children was quite low.

Not saying that one is better than the other, just that this seems the most plausible explanation I've heard so far.

Poor people used to have kids as a free work force and free elder support too. Pure selfishness. Today in Spain you are required to take care of your elder parents by law. Oh, back in the day often a third of the children died before reaching age 3 under very recently relatively speaking.

So, that's it. Conservatives love to bitch out about family duties, because once you are a slave of your elder relatives ON TOP of your children caring, you will never succeed against rich people.

Dear Brits and Germans, think twice before settling down a family there because of an easy retirement.

Economics is a scapegoat for liberal policies that have backfired.

We simultaneously have the 'paradox of female unhappiness' that isnt a paradox at all; and male loneliness epidemic.

Pretty hard to have babies when men are lonely and women are unhappy.

Because we have a "No-Future"-ideology in the cultural lead - and no story lined up we wont to tell on, no societal level projects.

It's a bit of a meme at this point, isn't it?

Middle income countries like China have low fertility.

Lower-middle income countries like India are around replacement level (I think officially it's lower than replacement but lot of births are "unofficial").

West African fertility rates are high... but A LOT lower than they were 50 years ago, and still trending downwards.

Whatever the reason, it's happening everywhere.

I wonder if decades of fear mongering about birthrates might have something to do with it?