Fertility Links
Bryan Caplan on heritability; Jay P. Greene and Lindsey M. Burke on government causes; Noah Carl and Bo Winegard on population density as a cause; Dan Hess on culture as a cause
Bryan Caplan looks at the “heritability” of having a large family.
I recently decided to investigate this claim in the General Social Survey. (All respondents reside in the United States; if you have comparable results from other countries, please share in the comments). Specifically, I regressed number of children on the year of the survey, the respondent’s age, and the respondent’s number of siblings.
He finds only a modest effect of the number of siblings on the number of children. I found the linear regression results difficult to read. I suspect that peer behavior matters more than parental nurture, as Judith Harris says and Bryan buys, and also that peer behavior may even matter more than parental nature.
The Baby Boom was a social phenomenon. The contemporary Baby Bust is also a social phenomenon. My point about the “gene pool” is not that the survivors will inherit genes that lead them to want more kids, but that you will get a generation that includes fewer child-phobes and at some point the social cues will be to have larger families.
Jay P. Greene and Lindsey M. Burke write,
U.S. higher education policies provide enormous incentives for more people to attend universities, take longer to complete their degrees, select degrees with negative returns on investment, and pursue advanced degrees at much higher rates than if we did not have such programs. In particular, highly subsidized student loans encourage more people to enroll and remain in higher education longer than they would if they fully bore the cost of their schooling.
The Grad Plus program, which offers unlimited loan amounts for graduate school, induces more people to remain even longer in school for graduate degrees. And government occupation licensing with ever-expanding educational requirements push people to take these loans and remain in school for many years.
That has created an artificially extended adolescence for the bulk of American young people.
I recently made the same point, that what Jean Twenge calls the “slow lifestyle” is antithetical to fertility. But fertility has declined in many countries, so that it is doubtful that policies that are peculiar to the U.S. are a major cause.
As Mads Larsen points out, the overall correlate with lower fertility is female equality. We do not want the solution to be taking away women’s achievements. The challenge is to find cultural solutions that make women’s empowerment compatible with large families. As I have said before, in the dating environment this means nudging men away from their natural instinct to seek multiple partners and nudging women away from their natural instinct to seek only the highest-status partner. In the overall culture, it means reversing the anti-family ideologies that emerged in recent decades.
Noah Carl and Bo Winegard write,
Population density is barely associated with fertility rates across US states or EU member states. Nor is it consistently associated with fertility across countries. Comparing culturally similar places that vary in terms of density suggests it has little or no effect. And in the 19th-century, London’s marital fertility rate was similar to that of England as a whole.
Why are fertility and population density often strongly associated within countries? We suspect the primary reason is that family-oriented people prefer to live in suburban or rural areas than in big cities.
Dan Hess talks with Razib Khan. Hess thinks that we need to actively encourage a pro-natalist culture. We cannot wait for things to turn around.
They also point out that the sudden shift to a one-child policy in China was great for the economy, because it created a high ratio of workers to dependents. But after 40 years or so, you get the opposite problem, with many dependents and few workers.
Also, think about house prices. Hess predicts that prices in China will fall dramatically as population falls.
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Claudia Goldin distinguishes two patterns. ("Babies and the Macroeconomy," NBER Working Paper 33311, December 2024.)
One pattern is gradual decline in fertility in countries that developed modern economies over a long period. Her examples are the U.S., the U.K., Germany, France, Sweden, and Denmark. The other pattern is sudden, deeper decline in fertility in countries that developed rapidly since the 1960s. Her examples are Japan, Italy, Spain, Greece, Portugal, and Korea. She makes a case that the latter group has a "lowest low" birth rate due to emergence of a sharper battle of the sexes (conflict of norms between traditional men and modern women) in the context of rapid economic growth and massive migration from rural areas to cities.
Here (below) are excerpts from the gated article:
"Among the most astonishing facts in the history of the decline of fertility has been the plummeting of birth rates in tradition-bound countries in Asia, as well as in Catholic and Orthodox Europe. [... .]
to make sense of the fertility decline, we must also pay attention to the speed with which countries advance economically. Thus, the framework shifts attention to the macroeconomy—the rate of growth in GDP per capita (measured in constant price PPP for comparability) and the resultant migration from low-productivity rural areas to high-productivity urban areas. [... .]
Migration is important to the story of fertility change because those who move from rural areas enter the urbanized world having with more firmly-held beliefs and more traditional ways. Among the children of the migrants, the daughters gain more from modernity as they are offered considerably more options than they once had. The sons, however, gain from maintaining parts of the past. How much they gain is evident from the division of labor in the home. Men in developed countries that modernized very rapidly do considerably less housework and care for others in their homes, relative to women, than do men in countries that had more continuous growth experiences. [.... .]
Nations that had rapid and sudden economic growth and large movements of population from rural to urban areas experienced sharp drops in fertility. The declines far exceed those for nations that had more continuous growth and did not have substantial internal migration. These facts are consistent with the notions of the model that rapid change leads to disagreements between young men and women in part because of generational clashes for which sons agree more with their parents than do daughters. The model is also consistent with data on the fertility preferences of couples and their disagreement. [... .]
women spend more time with their children often by sacrificing their careers or by having lower incomes and thus becoming economically vulnerable. If they are divorced or separated, they and their children may suffer. They know this in advance and, in consequence, will resist having more children. But if fathers and husbands can credibly commit to providing the time and the resources, the difference in the fertility desires between the genders would disappear. [...] One method of commitment is to live in a country or state in which social opprobrium dictates that men provide the finances, time, and mental resources to the family. ... .]
The U.S. baby boom is one of the few examples of a country with TFR less than two that greatly increased. The baby boom was partly accomplished by glorifying marriage, motherhood, the “good wife,” and the home. Can a turnaround today be accomplished by glorifying parenthood, especially fatherhood, and changing workplace rules so fathers are not penalized by taking time off and requesting fllexible work arrangements? One thing is clear: unless the negative relationship between income and fertility is reversed, the birth rate will probably not increase."
As an older Gen-Xer, my highly unscientific and anecdotal observations:
1. I think peer behavior is probably the #1 cause. I remember when people my age started having children, the answer I heard the most when I asked "how did you know you were ready?" was "well, our other friends were starting families." And in my own experience, that was exactly what made me want a baby - two other couples we were friends with were having babies, and it made me think "hey - I could do that!" Not only does it reinforce the idea of "we're actually grown up enough to have a child," but there's also the incentive of "our kids can play together!" "we can go on family camping trips together!" "we can swap babysitting with each other!"
2. Corollary to #1 is that if childbearing is considered a bit declasse by one's social set, one is more inclined to be extremely vigilant about avoiding pregnancy. I grew up in a wealthy NYC suburb, and there really was a strong undercurrent of "having a baby in your 20s is low-class behavior; People Like Us have children at 35+ because we are educated and have careers." I moved away when I was in my early 20's to a part of the country where it was totally normal middle-class behavior to have children in your 20's, but I couldn't shake the visceral "ugh...trailer park!" reaction that I had. In fact, I still felt mildly embarrassed announcing my first pregnancy to my hometown friends - even though I was 31 and had been married for seven years. When I would visit my hometown, I would get some side-eye for being "so young" and having 3 children who were clearly not multiple births. It seemed that the "typical" mom was 45+ and had twins or triplets as a result of IVF or other fertility interventions.
3. Along with #2 is the widespread stigma of having more than 2 children. I live in a small town with a lot of large families (it is a pleasant, safe little town where kids were still sent outdoors to play without grownup supervision well into the 2000s); so I knew several families on my street with more than 4 children. However, when I announced my third pregnancy to my friends who lived in other towns, I got remarks like "haven't you two figured out what causes that yet?" "is this a religious thing?" or "sheesh, you're gonna have your hands full!" We even had some friends who were Asian who jokingly referred to us as their "white trash friends" because we had "so many kids" (ironically, the couple in question went on to have four children themselves).
4. Part of the reason that people have fewer children than they would really like to is that modern parenting for middle-class and upper-middle-class people involves a LOT of parental involvement. As I mentioned in #3, my town was a bit of an anomaly in that it was still considered totally OK to send your kids outdoors to play unsupervised; and because it is a small, walkable town kids were expected to transport themselves to and from school, dance class, sports practice, and part-time jobs by walking or riding their bikes. However, my friends in other surrounding areas were horrified by this - it seemed borderline neglectful to them. For the most part, people in my town also resisted the urge to enroll kids in dozens of extracurricular activities (probably because most of us had 3-4 kids and were conscious of expense, not to mention the unpleasantness of having to amuse tired, overstimulated younger children while their older sibling had their tuba lesson or whatever); but in many of the other nearby "nice" suburbs it was expected that your child would not only play year-round sports and study a musical instrument but would also do dance, Japanese lessons, SAT prep, and perhaps even have an "internship" before they even had a driver's license. That places a tremendous burden on parents, especially working parents who must spend all their non-work hours chauffeuring children to activities, or else spend considerable amounts of money to employ a nanny with a driver's license. All of this endless activity is usually justified as "looking good on college applications," and unfortunately I see this attitude growing in my little town these days as well.
Now, my children are young adults, and their friends are all rather anti-natalist, citing the expense and work involved in having children. To them, it seems like a family is some sort of status symbol that only rich people can have and that paradoxically doesn't seem like much fun, so you need to pay a nanny to deal with all the driving to and fro.
Also, Gen Z is notoriously pessimistic about things like being able to afford a home someday; somehow, they all got the idea that Boomers and Gen X were able to afford 2500SF homes without needing college degrees. I keep trying to point out that *my* parents were not able to buy a home until they were in their mid-30s, and that the home they did purchase was 800SF, they had one car, we ate out perhaps twice a year, our clothes were hand-me-downs and thrift-store items, and we never took a vacation other than visiting relatives - it was a very different standard for middle-class living in those days!