When buying on leverage is actively encouraged to the masses, a crash usually follows. Before the 1929 crash, buying stock/equites on extreme margins became normal; Before the 2008 crash, buying real estate on extreme margins became normal; today we are seeing higher education being purchased on extreme margins. Now higher education is a different beast than the others, so it is hard to say how a economic event stemmed from student loans will manifest itself, but it is a real concern.

I highly recommend JL Collins Stock Series blog posts and specifically this article on market events of the past 100 years: http://jlcollinsnh.com/2017/07/26/time-machine-and-the-futur...