Academic hiring committees play a role:
Robert Oprisko of Butler University found that half of the jobs in university political science programs went to graduates of the top 11 schools. That is to say, if you have a Ph.D. from Harvard, Stanford, Princeton and so on, your odds of getting a job are very good. If you earned your degree from one of the other 100 degree-granting universities, your odds are not. These other 100 schools don’t even want to hire the sort of graduates they themselves produce. They want the elite credential.
That is from David Brooks.