Earnings are difficult to compare due to the selection bias in admissions. Even if that weren't the case, you'd have to factor in the compounded interest from a

Earnings are difficult to compare due to the selection bias in admissions. Even if that weren't the case, you'd have to factor in the compounded interest from all of the money spent on schooling as well as that of the money not earned during those four years. Additionally, there's the cost of delaying and/or slowing one's education while spending those years schooling (which generally moves at a glacial pace). There are some cases in which the schooling truly is worth the cost and yields exceptional results for those admitted (as opposed to only admitting those who would be exceptional regardless). Those cases are rare and getting rarer.