The correlation between IQ/education and fertility is also weaker in highly educated nations, which could explain why the effect is attenuated past that point. Some of it is because education causes income which causes fertility, but the education itself makes people have less children than they otherwise would.
It’s just the prime time age range thing. It also lines up with the 10 yr estimate.
•Girl turns 18, goes to college for 10 years, now she’s 28.
•Amish girl or whatever culture turns 18, starts having kids at peak fertility. At 28 yrs old she might have 4 kids already.
The question and ‘mystery’ gets a lot simpler if you use the analogy of elite male sportsmen, let’s call them football players. The prime time for them is 20-30 and they’re basically washed up starting from 31 and getting geometrically more severe with each additional year. It’s just the biology. No one argues it. When it’s women though people lose their minds.
Good point. As a hasty defense maybe the girls who decide to pursue higher education lock in early. Like, since school is segmented into unadjustable sizes (4 yr college, you generally can’t graduate at grade 10, etc) the reason the >10yr mark doesn’t change anything is that they are locked into the low fertility train for many many years from the moment they say “yes, I am getting more educated”.
Some studies in poor African countries find that sending girls to school for an additional year does reduce childbearing.... But this estimate might not actually hold for higher levels of schooling; it doesn’t really tell us what happens when you go from, say, 9 to 14 years of female education. Chen (2022) looked at an expansion of higher education in China, and found that it actually raised birth rates by a significant amount. Monstad et al. (2008) found zero effect of education on fertility in Norway, and Cummins (2025) find zero effect in England.
Not so sure on your interpretation here. The big story is that increased education is indeed associated with decreased fertility. That little uptick doesn't seem terribly important, and yet you hang much of your interpretation on it. Even if we allow it, the question is how to interpret it. I think we know that there can be a strange hypocrisy or contradiction among the elite - they champion progressive social programs that serve to destroy the family, yet they themselves invariably enjoy the benefits of traditional family structures. I can well imagine that those women who earn MAs and PhDs will recognize the need for traditional families, whereas those with merely the BA level (the vast majority) get psyoped into thinking that career will satisfy them.
It is absurd to deny that more women working is not related to this decline, starting in 1980.
Are there other causes? Yes. Feminism and hate speach against males being also one.
After COVID is also after the MeToo pick, which happened only few years before. So having in mind that It takes around 5 years from the couple formatio till the time you have a kid, you have your answer to the post COVID decline.
There is only 1 solution: raise the status of men.
Which, btw, is fair.
Men cannot longer account 40% of degrees. Its a shame for the "equality view" of feminism. And also for fertility rates.
Could be something to do with work and male earning potential, but unlikely that feminism is a big cause when the collapse is happening across various places outside the anglophone world, with even India and Indonesia soon going sub replacement.
Countries that are the most culturally "feminist" doesn't accurately predict which are the lowest TFR.
Education of women (feminism) has a strong correlation with TRF.
There are extremely rich countries where the TRF is sligthly over, but even those countries are far below 2.1.
Its easy: having a kid, requieres dedicstion. If you are having a women being a 12h lawyer, she Will not have more than 1 or 2 kids. If you are poor, even worst.
India is above 2, and It is living to a feminist country where women work.
I will have to Look at raw Data myself later, but why focus so much on the upward tail? It’s doesn’t matter at some point. These females Are basically housewives who have no desire to work anyway. For them it’s just a hobby to be in education to catch wealthier men. The problem is that people don’t have children at 20-25. Which is the steepest point in the graph.
Obviously, the debate is about infinite college degrees for women and the fertility trade-off, but the data suggests this is not an issue. The fertility decline is not caused by female higher education.
Women being more than 10 years in higher education basically don’t need to work anyway. So they are outliers in any sense.
The general trend that you do t have kids if you are busy with education holds still true.
It may also be that men work later in life due to their prolonged education and having a child literally takes 2. And people tend to build relations within their social circles and castes so both sexes delay having kids if they belong to the higher education casts.
It's also a problem, because those are literally peak fertility years, and if you wait until your early thirties to have your first kid (which is the median in the US and UK), you'll have burned through ~60% of your cumulative fertility to that point (area under the curve before age 30 in below graph):
Known by who? I know girls whose periods were really messed up by the COVID vaccines, and that's pretty linked with fertility. Your graph shows TikTok being popular before COVID and TikTok itself wasn't fundamentally different to Instagram or earlier forms of social media.
By evidence, you presumably mean papers by academics who are all selected for compliance with the collectivist ideology that drives vaccine fanaticism, or doctors who lose their license if they rock the boat. That kind of evidence.
Oh well. Alright then. Here's a paper saying that around half of all women had menstrual problems immediately after vaccination:
I'm surprised you didn't hear anything about that from the women you know in your own life. It wasn't a subtle problem. Many women had such difficulties.
All this is in the context of slowly discovering many other nasty things about the vaccines, all of which were denied at the time and most of which still are. The censorship on this topic is extreme and journalists twist themselves into pretzels trying to avoid obvious conclusions e.g. sudden drops in birth rate are due to climate change. The comment sections on such stories are always grimly hilarious, as none of the readers buy it.
So given a choice of very weakly correlated factors that have been around for a long time and in which there's no clear causal explanation, or, an experimental drug that excluded pregnant women during trials and was then mass administered to them, Bayes says B.
None of the women I know ever mentioned this, and no one mentioned this to me before you did. In any case, none of the studies really show what you need. They provide some indirect evidence. A 1-day delay in periods makes no practical difference, slightly reduced sperm counts for some months will not make much difference either to fertility. I would also expect many of these studies to be fakes, as with much other COVID material from 3rd world (e.g. fake studies about Ivermectin).
If you mean the first study, it's a review paper and says: "Most of the studies (12 out of 14) were from developed countries (Saudi Arabia, USA, Norway, UK, and Italy) while only 2 studies were conducted in underdeveloped nations of East Africa." Although I'd expect less fakeness from the third world in this case, tbh, despite it usually being the other way around.
The "1 day of change" finding comes from a study in which "this sample was not representative of the majority of women residing in the United States" and I don't believe it's accurate. Certainly the impact was much larger amongst my wife's group of friends; one of them lost their period for >6 months. She was unable to get any medical help, most doctors told her they couldn't help if it was vaccine related either because of lack of knowledge of what to do, or because it wasn't an officially recognized side effect.
This paragraph is an accurate reflection of what her group experienced:
"In a Norwegian cross-sectional survey based on 5756 women recruited via random sampling, around 39%–41% of women experienced some form of post-vaccination menstrual change.20 Symptoms included heavier bleeding, longer as well as shorter than usual cycles, unexpected breakthrough bleeding in those using contraceptives, and dysmenorrhea. Such symptoms were experienced more frequently following the second dose.16 , 18 , 20 "
You are more or less predicting the dynamic incapacitation effects and how women have children latter due to education in semi-mechanical way by shifting the decision into the future bc a government makes them sit through classes. It can lead to lower cohort fertility if it's not realized down the road, but leads to longer time between cohorts for sure.
Migrations were slowed down by COVID, so that would decrease fertility. Post-COVID migration booms have unclear effects on fertility. Housing more expensive is negative, but influence of breeding age people is positive.
> Female education does seem to cause lower fertility, but stops having an effect around 10 years of schooling.
If you're going to go the eliminating women's education route to raising fertility, you would have to go way beyond universities, i.e. literal "White Sharia" meme LOL.
Have you considered that increased exposure to environmental factors besides "social media" as potential causes of the reduction in fertility in recent years? Screens have been around for a while. On the other hand, factors such as COVID, heatwaves, and diminishing purchasing power have increased markedly since 2020.
COVID is just a random virus for most people of breeding age. COVID lockdowns however may have slowed family formation quite a bit. Heatwaves are not new. I don't think there's any lower purchasing power except for housing in Anglo countries, but other countries show the same pattern.
The effect within individuals is a lot weaker than the effect between nations, which suggests confounding or large group-level effects.
The correlation between IQ/education and fertility is also weaker in highly educated nations, which could explain why the effect is attenuated past that point. Some of it is because education causes income which causes fertility, but the education itself makes people have less children than they otherwise would.
https://www.econlib.org/archives/2011/06/kids_are_normal.html
It’s just the prime time age range thing. It also lines up with the 10 yr estimate.
•Girl turns 18, goes to college for 10 years, now she’s 28.
•Amish girl or whatever culture turns 18, starts having kids at peak fertility. At 28 yrs old she might have 4 kids already.
The question and ‘mystery’ gets a lot simpler if you use the analogy of elite male sportsmen, let’s call them football players. The prime time for them is 20-30 and they’re basically washed up starting from 31 and getting geometrically more severe with each additional year. It’s just the biology. No one argues it. When it’s women though people lose their minds.
goes to college for 10 years?
That level of education would be off the chart 12+10 = 22 years of education?
Doesn't the data show that 10 years total is the big decline, with some small recover at 12 years (high school graduate)?
Good point. As a hasty defense maybe the girls who decide to pursue higher education lock in early. Like, since school is segmented into unadjustable sizes (4 yr college, you generally can’t graduate at grade 10, etc) the reason the >10yr mark doesn’t change anything is that they are locked into the low fertility train for many many years from the moment they say “yes, I am getting more educated”.
From a recent Noah Smith post:
Some studies in poor African countries find that sending girls to school for an additional year does reduce childbearing.... But this estimate might not actually hold for higher levels of schooling; it doesn’t really tell us what happens when you go from, say, 9 to 14 years of female education. Chen (2022) looked at an expansion of higher education in China, and found that it actually raised birth rates by a significant amount. Monstad et al. (2008) found zero effect of education on fertility in Norway, and Cummins (2025) find zero effect in England.
https://www.noahpinion.blog/p/at-least-five-interesting-things-4c7?utm_source=post-email-title&publication_id=35345&post_id=167476849&utm_campaign=email-post-title&isFreemail=true&r=39c1o4&triedRedirect=true&utm_medium=email
Not so sure on your interpretation here. The big story is that increased education is indeed associated with decreased fertility. That little uptick doesn't seem terribly important, and yet you hang much of your interpretation on it. Even if we allow it, the question is how to interpret it. I think we know that there can be a strange hypocrisy or contradiction among the elite - they champion progressive social programs that serve to destroy the family, yet they themselves invariably enjoy the benefits of traditional family structures. I can well imagine that those women who earn MAs and PhDs will recognize the need for traditional families, whereas those with merely the BA level (the vast majority) get psyoped into thinking that career will satisfy them.
It's not that small an 'uptick'.
There is data on this, and indeed, grad degree obtainers (1.4 - 1.5) do have higher fertility than undergrad (~1.3).
https://imgur.com/a/GqecW0A
It is absurd to deny that more women working is not related to this decline, starting in 1980.
Are there other causes? Yes. Feminism and hate speach against males being also one.
After COVID is also after the MeToo pick, which happened only few years before. So having in mind that It takes around 5 years from the couple formatio till the time you have a kid, you have your answer to the post COVID decline.
There is only 1 solution: raise the status of men.
Which, btw, is fair.
Men cannot longer account 40% of degrees. Its a shame for the "equality view" of feminism. And also for fertility rates.
Could be something to do with work and male earning potential, but unlikely that feminism is a big cause when the collapse is happening across various places outside the anglophone world, with even India and Indonesia soon going sub replacement.
Countries that are the most culturally "feminist" doesn't accurately predict which are the lowest TFR.
https://x.com/peterrhague/status/1941870245272047630?s=48&t=pLFHEg2L61-4Vf7dy7shDw
Education of women (feminism) has a strong correlation with TRF.
There are extremely rich countries where the TRF is sligthly over, but even those countries are far below 2.1.
Its easy: having a kid, requieres dedicstion. If you are having a women being a 12h lawyer, she Will not have more than 1 or 2 kids. If you are poor, even worst.
India is above 2, and It is living to a feminist country where women work.
I will have to Look at raw Data myself later, but why focus so much on the upward tail? It’s doesn’t matter at some point. These females Are basically housewives who have no desire to work anyway. For them it’s just a hobby to be in education to catch wealthier men. The problem is that people don’t have children at 20-25. Which is the steepest point in the graph.
Obviously, the debate is about infinite college degrees for women and the fertility trade-off, but the data suggests this is not an issue. The fertility decline is not caused by female higher education.
I am not sure how you come to that conclusion.
Women being more than 10 years in higher education basically don’t need to work anyway. So they are outliers in any sense.
The general trend that you do t have kids if you are busy with education holds still true.
It may also be that men work later in life due to their prolonged education and having a child literally takes 2. And people tend to build relations within their social circles and castes so both sexes delay having kids if they belong to the higher education casts.
As you can see in the results, the causal claim fails to hold.
It's also a problem, because those are literally peak fertility years, and if you wait until your early thirties to have your first kid (which is the median in the US and UK), you'll have burned through ~60% of your cumulative fertility to that point (area under the curve before age 30 in below graph):
https://imgur.com/a/DCff1fl
Graph from Geruso, Age and Infertility revisted (2023)
Why would social media be any different post COVID? Social media has existed since 2005 or so. Seems more likely to be vaccine related.
No vaccine is known to cause that kind of side effect, so no, that is not very likely.
Tiktok https://trends.google.com/trends/explore?date=all&q=%2Fg%2F11f555cn8l&hl=en
Known by who? I know girls whose periods were really messed up by the COVID vaccines, and that's pretty linked with fertility. Your graph shows TikTok being popular before COVID and TikTok itself wasn't fundamentally different to Instagram or earlier forms of social media.
Random anecdotes stuff does not belong here. If you know of any evidence showing fertility effects of any other vaccine, then post it.
By evidence, you presumably mean papers by academics who are all selected for compliance with the collectivist ideology that drives vaccine fanaticism, or doctors who lose their license if they rock the boat. That kind of evidence.
Oh well. Alright then. Here's a paper saying that around half of all women had menstrual problems immediately after vaccination:
https://pmc.ncbi.nlm.nih.gov/articles/PMC9294036/
I'm surprised you didn't hear anything about that from the women you know in your own life. It wasn't a subtle problem. Many women had such difficulties.
Not only for women. Here's the effect on sperm counts: https://pubmed.ncbi.nlm.nih.gov/35713410/
And another: https://journals.lww.com/apjr/Fulltext/2023/12020/Effect_of_BNT162b2_mRNA_COVID_19_vaccine_on_sperm.3.aspx
All this is in the context of slowly discovering many other nasty things about the vaccines, all of which were denied at the time and most of which still are. The censorship on this topic is extreme and journalists twist themselves into pretzels trying to avoid obvious conclusions e.g. sudden drops in birth rate are due to climate change. The comment sections on such stories are always grimly hilarious, as none of the readers buy it.
So given a choice of very weakly correlated factors that have been around for a long time and in which there's no clear causal explanation, or, an experimental drug that excluded pregnant women during trials and was then mass administered to them, Bayes says B.
None of the women I know ever mentioned this, and no one mentioned this to me before you did. In any case, none of the studies really show what you need. They provide some indirect evidence. A 1-day delay in periods makes no practical difference, slightly reduced sperm counts for some months will not make much difference either to fertility. I would also expect many of these studies to be fakes, as with much other COVID material from 3rd world (e.g. fake studies about Ivermectin).
If you mean the first study, it's a review paper and says: "Most of the studies (12 out of 14) were from developed countries (Saudi Arabia, USA, Norway, UK, and Italy) while only 2 studies were conducted in underdeveloped nations of East Africa." Although I'd expect less fakeness from the third world in this case, tbh, despite it usually being the other way around.
The "1 day of change" finding comes from a study in which "this sample was not representative of the majority of women residing in the United States" and I don't believe it's accurate. Certainly the impact was much larger amongst my wife's group of friends; one of them lost their period for >6 months. She was unable to get any medical help, most doctors told her they couldn't help if it was vaccine related either because of lack of knowledge of what to do, or because it wasn't an officially recognized side effect.
This paragraph is an accurate reflection of what her group experienced:
"In a Norwegian cross-sectional survey based on 5756 women recruited via random sampling, around 39%–41% of women experienced some form of post-vaccination menstrual change.20 Symptoms included heavier bleeding, longer as well as shorter than usual cycles, unexpected breakthrough bleeding in those using contraceptives, and dysmenorrhea. Such symptoms were experienced more frequently following the second dose.16 , 18 , 20 "
You are more or less predicting the dynamic incapacitation effects and how women have children latter due to education in semi-mechanical way by shifting the decision into the future bc a government makes them sit through classes. It can lead to lower cohort fertility if it's not realized down the road, but leads to longer time between cohorts for sure.
that was a long post to basically say: yes it's a cause.
I think part of the post covid fertility crash is just migrations to big western countries and city centers, so there is that offset effect.
Migrations were slowed down by COVID, so that would decrease fertility. Post-COVID migration booms have unclear effects on fertility. Housing more expensive is negative, but influence of breeding age people is positive.
> Female education does seem to cause lower fertility, but stops having an effect around 10 years of schooling.
If you're going to go the eliminating women's education route to raising fertility, you would have to go way beyond universities, i.e. literal "White Sharia" meme LOL.
Great data, great graphs. Need to read it again, more carefully. Thanks
Have you considered that increased exposure to environmental factors besides "social media" as potential causes of the reduction in fertility in recent years? Screens have been around for a while. On the other hand, factors such as COVID, heatwaves, and diminishing purchasing power have increased markedly since 2020.
COVID is just a random virus for most people of breeding age. COVID lockdowns however may have slowed family formation quite a bit. Heatwaves are not new. I don't think there's any lower purchasing power except for housing in Anglo countries, but other countries show the same pattern.