http://www.american.com/archive/2007/august-0807/backing-back-to-school
Yes, but as the author also points out, for an average investment of about $20,000, the average person makes over half a million dollars over a lifetime, so how can we be "overinvesting" in higher education if the financial rewards are still so high?
On the other hand, I tend to agree that our overall standards in higher education have declined and that we're probably enrolling as many or more people in college than our economy really needs. See this article for those arguments.
http://article.nationalreview.com/?q=NGY0NmY3MzMzOWU1NDZmYmE0MTE0NGJkZGVmYzNiZWU=