>But better knowledge will always be important for social mobility, at the very least via earning more money. College doesn't only improve your income via teac

>But better knowledge will always be important for social mobility, at the very least via earning more money. College doesn't only improve your income via teaching you valuable skills that demand a higher wage on the job market. It also tells employers that you're the sort of person who can successfully get through college, and employers rightfully discriminate based off this signal. Furthermore, there's a selection effect too. Colleges don't necessarily make their students better, but can often simply find better students. If you took Stanford and replaced 100% of the instruction with putting the admitted kids in a room together, the "graduates" would end up out-earning others simply because of the kind of person that they are. There's some debate about the relative sizes of these three factors, but it's my opinion that the human capital theory is a relatively small portion of it. Under 20%, I think.