[pacbard]

The most likely explanation for this phenomenon is that there isn't a change in the population average for variable X, but that the decrease in college students' average X is due to an increase in population college going rates.

Looking at the statistics[1], the US went from a 23.2% college completion rate in 1990 to 39.2% completion rate in 2022, or a 67% increase in college degree completions. If you assume that X in the population is constant over time, mechanically you will need to enroll and graduate students from lower percentiles of X in order to increase the overall college completion rate in the whole population.

This process might be particularly acute at "lower tier" institutions that cannot compete with "top tier" institutions for top students.

[1]: https://nces.ed.gov/programs/digest/d20/tables/dt20_104.20.a...

[travisjungroth]

I don't think the increase is big enough. A 67% increase means the "new" students are 41% of the population. But these reports are coming from all over the place and describing the majority of their class.

You can also see it in the whole pipeline. Everything he described is true (age adjusted) for K-12 as well.

[scythmic_waves]

This particular professor has been teaching for 30 years. I'm not sure I find your explanation all that convincing in light of that, especially since this isn't an isolated opinion.

I'm much more interested in how much the average student has had a phone to distract them during their lifetime. For the incoming 2025 class of 18 year olds, the iPhone came out the year they were born. So potentially 100%. I expect that plus the availability of LLMs is a deadly combo on an engaged student body.

[mgraczyk]

Based on the intro of the article, the university where this professor works is likely below median. Each year the typical student at his/her university is worse because the best students go to better schools

[jkhdigital]

That most likely explains the slow creep of grade inflation, remedial courses, etc. which has been going on for decades. This article touches on that but mostly describes an entirely different phenomenon.