[LAC-Tech]

I get the impression one year masters, 3 year PHDs, etc, were much more common in the mid 20th century.

I presume financial incentives dragged out how long degrees like this take now. That, or everyone is dumber, which seems unlikely.

[CorrectHorseBat]

Or there's more to learn now and all the "easy" PhD subjects are already taken?

[LAC-Tech]

Yeah that could be it. (I'm idly speculating without any knowledge or research. It's just unlike a lot of people here I admit it)

Maybe there's some ideal ratio between "current novelty levels" and "number of PhD candidates".