“Schools like Harvard and MIT have the students who make the highest median income, because they get the most driven students.”
I agree with this much. However…
“The schools themselves don’t actually do anything for them.”
I wouldn’t go so far as to say that the schools don’t do “anything”. I would say that the difference between incoming students is the dominant factor in the difference in results, but not necessarily the only factor (especially if we start comparing MIT and Harvard with anything ranked lower than about 500 or 1000 – which admittedly might be a silly comparison).
Given the original title of this thread, there is another thing that bothers me in the original title which we probably have overlooked (or at least not picked on sufficiently). This is the word “only”. Even if I were to agree that going to a highly ranked university would cause my child to make more money, I still wouldn’t agree that prestige and money are the “only” things that should be considered.