Don't have data, but just imagine that you are a recruiter looking at two resumes, one from MIT/CMU/etc. and the other from lesser-tier universities, which one would you give a chance of interview to? Now imagine you have 2,000 resumes.

Or, imagine how many premium SV start-ups have those MIT/CMU/etc. guys and what advantage you can leverage if you come out fresh from the same university. Maybe you are even taught by the same prof :D