[sb057]

From a layman's perspective, it seems like it's mostly an expected outcome of college degrees becoming a class signifier. In 1990, only a fifth of American adults had bachelor's degrees, with those who held them making 70% more than high school graduates. A sizeable gap, sure, but those non-college graduates have minimum wage retail workers and general laborers, and union steel and auto workers in the same educational bucket.

By 2020, it had risen to well over a third of Americans who had bachelor's, and 105% more income for those with them. One might expect a dilution in a degree's value, but I think it's just a matter of minimum wage workers still being high school graduates, whereas virtually all professional workers (including the increasingly few manufacturing workers) needing a bachelor's to get past the first stage of HR.

[1] https://educationdata.org/education-attainment-statistics

[2] https://en.wikipedia.org/wiki/Educational_attainment_in_the_...

[ajross]

I don't follow? If the population of college educated adults is growing, it's by definition becoming less selective and would be expected to show less skew. College educated people used to be a "special" demographic, now they're much closer to the rest of society. But the data shows the opposite effect, with the lifespan benefit of a degree more than doubling.

[asdff]

I think there is something to be said about provenance of the degree. For example there's been quite a lot of expansion in number of colleges or even community colleges expanding their systems while actual prestigious colleges themselves have only expanded so much.

Here are the stats for Harvard enrollment of undergrads (1,3), along with US population (2,4) and percent Harvard student (not sure where I get number of people in the workforce with harvard degrees data but maybe this is a decent proxy):

Year - ugrads - US population - % of US pop at harvard

1990 - 22,851 - 248,709,873 - 0.0092%

2000 - 24,279 - 281,421,906 - 0.0086%

2010 - 27,594 - 308,745,538 - 0.0089%

2025 - 24,519 - 343,000,000 - 0.0071%

1. https://nces.ed.gov/programs/digest/d13/tables/dt13_312.20.a...

2. https://www.census.gov/data/tables/time-series/dec/popchange...

3. https://www.harvard.edu/about/

4. https://www.census.gov/popclock/

[kelipso]

Let me just write this down… Just for illustration, assume average lifespan of poor person is 60 and average lifespan of rich person is 80, 30% of the population is from the rich person group and rest from the poor person group, and these two facts hold for current time and the 90s.

Let’s say currently, every rich person goes to college, so college to non-college lifespan is 80:60.

While in the 90s, let’s say 20% goes to college and every college going person is rich. Then the lifespan of college going person would still be 80 and non-college going person would be more than 60.

So, another way of looking at it is that the non-college going population is getting to be the special demographic whose statistics are getting skewed, though I’m not sure that’s the correct way of looking at it.

[rayiner]

It might be a skewed distribution where life expectancy drops off rapidly below the median but isn’t that different at the top. So it’s not a big difference when it’s the bottom 90% and the top 10%, but it is when it’s the bottom 60% versus the top 40%.

[ajross]

Well, sure, but generally when your hypothesis demands a highly non-linear distribution function to make sense, it's just wrong. That might be true; the math could be made to work. But if it were, that is the result the study would be pushing and not the bland thing about smoking.

It's a smell test thing, basically.

[LorenPechtel]

Why shouldn't it be non-linear? Non-linear is what I would expect--the educated know enough to avoid a range of stupid behaviors that lower life expectancy. You see few of the life-destructive behaviors in the degreed group. You also would have seen the same effect in many of the non-degreed individuals but the data didn't separate them. More degrees, more of the careful people move from the non-degreed pool to the degreed pool and the gap between the pools rises.

There's also the factor that simply getting a degree screens out many of the people that engaged in such behaviors.

[rayiner]

I think that's basically correct, but you don't even have to put it in quite those terms. Life expectancy measures are dominated by early deaths. The group of people without a college degree probably includes most of those who are likely to die early (teen moms, structurally unemployed, lumberjacks or electrical linemen, etc.) It also includes a bunch of people without those risk factors (administrative assistants, etc). So as more of the latter group get a degree, the high-risk population comprises a greater and greater share of the group without a degree.

[rayiner]

I don't think it would require a weird distribution. Average life expectancy is dominated not by people living a really long time, but by a minority of people dying really early (due to child/maternal mortality and work-related or accidental deaths). If those people are concentrated among those without a college degree, then you'd see the life expectancy of people without a college degree declining as a greater share of the population goes to college.

[asdff]

10% increase is a lot lower than I anticipated what with all the talk about a B.S. being the barrier for entry these days.

[foundddit]

Apparently nearly half of college students drop out. [1] That gives us most people going to college, but a significant portion not graduating.

[1] https://educationdata.org/college-dropout-rates

[red-iron-pine]

stats also show that the average student is now taking longer to graduate, easing towards ~6 years instead of 4

takeaway is probably that a lot of not-really-qualified students are going to 4-year schools and probably shouldn't.

[tobyjsullivan]

20% to 33% is not a 10% increase, if that’s what you’re referring to. That’s a 65% increase.

[Spartan-S63]

Even still, over more than two decades, only a ten percentage point increase is still somewhat mind-blowing.

As someone who grew up upper middle class in a wealthier suburban area, I lived in a bubble where the vast majority of people I went to high school with went off to college and got bachelors degrees. To me, it seemed that that was the norm for most Americans, but that's far from reality.

[asdff]

65% increase seems big but this also means only 13% more adult americans are degree holders which seems remarkably paltry to me after almost 40 years of "thou shall go to college" being preached to highschoolers.

[jchallis]

Only about half of Americans who go to college finish their degree. The saddest part of the college debt crisis are the kids with debt and no degree to pay it off.

[SequoiaHope]

College got very expensive. If it hadn’t I’m sure we’d see higher numbers.

[asdff]

I think that depends on if you go out of state or in state. My alma mater has frozen in state tuition for at least 10 years now, maybe longer. Plenty of flagship in state schools are only around 12k-15k a year. In a world where you can now crack 15 an hour unskilled now while living with the parents over the summer you can probably cover a lot of that almost like it was in ye olden times.

[SequoiaHope]

Seems like things have been relatively flat for the last decade, but costs are roughly double what they were 30 years ago.

https://www.npr.org/2025/11/20/nx-s1-5600854/college-costs-h...

[rendaw]

GP means a "plus ~10%" not a "times ~1.10" increase.