Avent's sensible take on over-education:
Who do you suppose is feeling better about job prospects now: the 85% of mail carriers without college degrees or the 15% with them? In a volatile labour market, the flexibility of a credential is of crucial importance.
America's education system could certainly use more flexibility, particularly where adult education and retraining is concerned. But the American economy could use more college graduates, and the pursuit of flexibility shouldn't detract from the goal of increasing overall educational attainment.
He follows up here.