More intellectual laziness in this thread. To start, what definition of bubble are you using? Where no plausible scenario can justify forward valuations? Where there is evidence people are doing transactions for the sole reason to flip the assets at a higher price?

Because even if you don't think it's "likely," I can think of plenty of cases where student loan data makes "sense" or is "logical," and you've provided no evidence (of which there is usually at least online anecdotal evidence, see: Dotcom Crash, Bitcoin) that people are making these loans solely to flip them. If you try to argue that the Loan-to-Originate model leads to this behavior, you may have to reconcile a lot of things in this paper: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2700179