To understand why we have a student loan crisis – and with $1.6 trillion in outstanding student debt, it surely is a crisis – just look at the U.S. bankruptcy code.

In 1965, Congress passed the Higher Education Act, part of President Lyndon Johnson’s Great Society. On the one hand, the new law established federal grants and loan programs to ease the monetary burden of attending college, especially for disadvantaged students. On the other hand, the bill included rules that made it difficult to discharge a federal student loan in bankruptcy. Over the next four decades, Congress added additional restrictions that made it not just difficult but impossible to shed a federal student loan, no matter how dire a borrower’s circumstances. In 2005, Congress crossed the final frontier: It added privately issued student debt to its no-discharge list.

Joe Nocera is a Bloomberg Opinion columnist covering business. He has written business columns for Esquire, GQ and the New York Times, and is the former editorial director of Fortune. His latest project is the Bloomberg-Wondery podcast “The Shrink Next Door.”