Sicker and stupider
Did you know that, on average, Americans are getting sicker and stupider every year? Ok, that’s stating the obvious, but did you know that this trend started suddenly around 1947?
In the latest edition of the American Economic Review, Nicholas Reynolds documents a surprising change in trends across the American population in key indicators for health and human capital. The charts below illustrate six key variables and their trends around 1947.
Panel A shows the average hourly wage of men by cohort. Starting after the Second World War, the average hourly wage of employed men adjusted for their age has declined. Meanwhile, the average number of years of schooling plateaued around the same time (Panel E), while women’s years of education (Panel F) continued to increase.
On the health side, mortality rates suddenly started to rise again after the Second World War and only returned to previous declining trends in the mid-1960s (Panels C and D).
Age-adjusted outcome by birth cohort
Source: Reynolds (2025)
So, yes, compared to their grandparents at the same age, today’s baby boomers (born between 1945 and 1965) are not much better educated and not that much healthier, but most definitely are making less money when adjusted for inflation. And that is just the baby boomer generation.
What has caused these peculiar shifts? Reynolds suggests two possible explanations, both of which require more research to be confirmed.
The first theory is that because there were more of them, baby boomer kids suffered from more intense competition for resources. Classrooms in schools were larger, and doctors had to deal with more patients, which reduced the quality of education and healthcare that baby boomers received.
The second theory is environmental. After the Second World War, cars became truly ubiquitous on American roads. However, until the 1970s, these cars ran on fuel that contained lead, a substance now known to be detrimental to the brain development of children and young adults, and generally harmful to health. It is so bad that there is a case to be made that the person who invented lead fuel additives may have killed more people on the planet than any other human.
In particular, the renewed improvement in health outcomes for people born after 1960, as shown in the charts above, indicates that the removal of lead from the air may have been one of the best things we have ever done.
I've also read that additional factors could have contributed to the observed phenomena:
1) Although newer cohorts benefited from better childhood nutrition and socioeconomic environments, these were offset by elevated early-life disease exposure, rising obesity rates, and stress caused by more precarious labor market conditions (e.g., job instability, shorter tenures) which explain observed declines in health across cohorts.
2) "The long arm of childhood"; The Great Depression was devastating (1/3 of WWII draft-age men were ineligible due to malnutrition), with multi-generational impact. Socioeconomic status has profound and lasting effects on adult mortality, cognitive impairment, and functional health, even when adult status improves. Structural inequalities may have actually deepened in that period, undermining cohort health outcomes even amid technological or medical progress.
3) Increased female labor-force participation post-WWII expanded labor supply and could have exerted downward pressure on wages overall, given both substitution and wage-compression effects in occupations. Also, US industrial dominance after WWII meant less global competition, so Boomers' strong wage growth was a unique artifact which eventually proved unsustainable.
Frankly, I've always suspected that the advent of television on a mass scale is under-studied as a causal factor. Television’s mass adoption after 1947 may have acted as a hidden cohort shock by subtly reshaping education, health, social life, and culture. For children, it displaced reading and sustained attention with more passive media, likely contributing to the plateau in schooling and cognitive development. Health-wise, hours of sedentary viewing encouraged snacking, disrupted sleep, and laid the groundwork for later obesity trends. Socially and economically, TV advertising fueled consumerism while reducing civic participation and productive leisure, weakening both savings and social capital. Politically, it rewarded image over substance and standardized cultural ideals, fostering conformity and new forms of competition. Together, these shifts suggest that TV may have functioned as a “soft environmental toxin,” not as obvious as lead but just as epoch-defining. It wasn't called "the boob tube" for nothing!
Too bad that the paper is behind a paywall. But it misses one thing: the curve of the decline in the total fertility rate is very similar to those shown. The decline started in 1951, and it keeps going. Pollution or social factors? probably both.