Earlier quoted context omitted.
No, the main question is are the highest paid workers getting that because of college, or did the most driven and smartest go to college, and would have been equally successful had no one gone to college? Back in the day (pre-WW2) most successful people did no go to college. College was for wealthy trust fund kids to spend some time meeting other wealthy trust fund kids, because there just weren't all that many colle…
Yes, that is precisely the question that has been asked & answered, and the general consensus in the academic literature (for example https://www.nber.org/papers/w7322 ) is that it’s both. The Fed paper I linked to here https://news.ycombinator.com/item?id=35212497 shows dramatically higher income and wealth premiums for educated people in the 30s and 40s, so you might want to take a peek.
This isn't answered by the paper you linked, which discussed the impact on individuals of college choice in a world where people do* go to college.