What caused the Great Depression to last longer than it should have?

The Forgotten Man, by Amity Shlaes. A very good book.

"The fact that the Depression dragged on for years convinced generations of economists and policy-makers that capitalism could not be trusted to recover from depressions and that significant government intervention was required to achieve good outcomes," Cole said. "Ironically, our work shows that the recovery would have been very rapid had the government not intervened."

Hmmm...this sounds sooo familiar for some reason.

Why Yes. Yes it does.