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AI Summary. The US currently has more 18-year-olds than at any point in history, but that population will decline 14% over the next decade.
Torsten Sløk ApolloCore argument: The 18-year-old population peaks today before declining 14% through 2034, reducing workforce entry cohorts and straining labor-dependent sectors.
America is at peak 18, and the number of 18-year-olds will fall 14% over the coming decade.AI Summary. Over 40% of young men identify as failures, with daily pornography use and daily gambling each associated with failure self-perception rates above 60%.
Joseph Davis, Michael Toscano and Ken Burchfiel Institute For Family StudiesCore argument: 42% of young men identify as failures, with daily pornography viewers (63%) and daily gamblers (66%) reporting self-perceived failure at rates roughly 1.5× the overall average.
More than half of young men in our survey are now gamblers. Nearly 1 in 4 (23%) report that they gamble daily, plus 12% doing so more than several times a week, and a further 21% at least some of the time. 43% of young men say they watch pornography daily (27%) or several times a week (16%), with another 26% about weekly or less. More than 4 in 10 young men (42%) believe that the statement “all in all, I am inclined to think that I am a failure” describes them “very well” (15%) or “somewhat well” (27%). Those who view pornography (63%) and gamble (66%) every day—along with day trading and playing fantasy sports—are significantly more inclined to see themselves as a failure.AI Summary. The relative price of raising children has not risen substantially compared to adult consumption, as rapid increases in childcare and tuition costs were offset by other components of household spending, leaving the overall child cost index roughly in line with adult benchmarks.
Christina Patterson and Heather Sarsons National Bureau of Economic ResearchCore argument: The Child Cost Index tracked closely with adult consumption benchmarks, as rapid childcare and tuition price increases were offset by other components of the child-rearing basket, leaving the relative price of children largely stable.
Figure 6 shows that real spending on children has increased substantially. Panel (a) plots real spending per child, deflated [by the authors’ new] child cost index, together with real spending per parent, deflated by [their adult cost index.] Both series rise by roughly one-half between 1990 and 2023 and move closely together over the medium run. Thus, households devote more real resources to children today than in 1990, but this increase appears to be part of a broader rise in household consumption rather than a child-specific expansion in required market inputs. Panel (b) reinforces this interpretation by plotting the share of total household spending allocated to children, separately by family size. Children absorb a large share of household resources in every year of the sample, but that share is strikingly stable over time within family size. Households with one child allocate just under 30% of total spending to that child in both 1990 and 2023. The sacrifice of adult consumption associated with children is therefore large, but it is not a recent development. Panel (b) also reveals clear economies of scale in child-rearing. Moving from one to two children raises the child share of household spending from roughly 30% to roughly 40%, far less than a doubling, and the incremental spending share falls further for larger families.AI Summary. GLP-1-driven weight loss reduces the female obesity penalty in marriage markets, with single women gaining an 18% higher probability of partnering and previously unemployed women gaining a 27% higher employment rate after 1.5+ years of treatment.
Rebecca Diamond Harvard UniversityCore argument: The largest magnitude change is in the marriage market.
BMI is flat before women start [GLP-1 treatment] and then falls (Figure 2, Panel A). All groups lose between 1.4 and 2.5 BMI points in the post period. These effects grow to between 2.7 and 4.2 BMI points at 1.5+ years after initiation. The largest magnitude change is in the marriage market. Women who are single when they start (Figure 2, Panel B) increase their probability of being married or living with a partner by 18.3 pp overall and 28.6pp (s.e. 7.1) at six or more quarters, building gradually as they lose weight. Partnered women’s relationships, by contrast, are stable. Their partnership probability barely moves (0.1 points, s.e. 1.8), and there is no excess relationship dissolution (0.0, s.e. 1.7). The marriage-market response is the making of new matches, not the breaking or remaking of old ones. In contrast, single women’s weight loss seems to dramatically affect first impressions of potential partners, leading to a large increase in marriage and cohabitation. This is consistent with prior work on the obesity penalty negatively affecting women in the marriage market. Figure 2, panels C and D show that women not employed at baseline move into work: their employment rate rises 13pp overall and 27pp after six or more quarters, and their weekly hours rise by nearly ten hours at the longer horizon.AI Summary. Teen birth rates fell sharply across high-income countries after 2007 as smartphone adoption shifted peer interaction from in-person to digital, reducing unstructured contact where most unintended teen conceptions occur. Each 10% rise in broadband or 4G coverage correlated with ~10–19 percentage point larger declines in teen birth rates, while teen
Nathan Hudson and Hernan Moscoso Boedo University of CincinnatiCore argument: U.S. teen birth rates fell 71% for ages 15–19 between 2007–2024 vs. 9% increase for ages 35–39, driven by smartphone-mediated.
Teen fertility collapsed almost everywhere in the world starting around 2007. This is a striking fact. Countries with very different healthcare systems, welfare regimes, abortion laws, religious traditions, recessions, and demographic trends all saw similar breaks in the same window. Whatever caused it was something global—something that arrived in roughly the same form in all of these places at roughly the same time… between 2007 and 2024, the birth rate among women 15–19 fell by 71 percent, 20–24 by 43 percent, 25–29 by 23 percent, 30–34 by 1 percent, and 35–39 rose by 9 percent… U.S. teens reduced in-person socializing from 68 minutes per day in 2003 to 38 in 2019 while computer-leisure rose from 22 to 96 minutes… Under-18 conception rates accelerated from −1.3 percent per year pre-2007 to −8.9 percent post-2007, a 6.8x acceleration that nearly matches the U.S. 5.6x acceleration.AI Summary. Global birth rates are falling faster than predicted, driven primarily by fewer people forming couples rather than couples having fewer children. Smartphone adoption timing correlates with birth rate declines across countries at different income levels, while housing costs, education gaps, and government subsidies explain only part of the trend.
John Burn-Murdoch Financial TimesCore argument: Why Birth Rates Are Falling Everywhere All At Once.
US, British and Australian birth rates for teens and young adults were broadly flat during the early 2000s but began to fall markedly from 2007. The same slide began in France and Poland around 2009, and in Mexico, Morocco and Indonesia around 2012. What had been steady declines in fertility in Ghana, Nigeria and Senegal became precipitous drops between 2013 and 2015. All of these inflection points coincided with the mass adoption of smartphones in local markets — as measured by Google searches for mobile apps. In country after country the birth rate plunged after the introduction of smartphones, no matter what the previous trend was. The younger the age group, the more pronounced the downturn — a mirror image of smartphone usage patterns.