None. It is a fact that graduates of top-drawer schools do better. But do those graduates do better because they went to top-drawer schools?
This question has actually been studied. The researchers looked at graduates who were accepted to elite colleges, but chose to attend less selective colleges, say, public universities. And those graduates did just as well as their Ivy-league counterparts. What matters is what the student brings to their college education.
Fame does not equal qualilty, and I encourage you to look beyond the name-brand schools. There are many many less-selective – which does NOT mean “inferior” – schools which provide a very fine education, and a good launch into adult life.