Pretty much every single bust since 1870 has been the explosion of a credit bubble. Cheap credit is the heroin of democracies. In the short term, it's like free money. It's cheaper to buy stuff, and it doesn't result in higher taxes. Politicians are always for it. The cheap money will endear them with the population in the next election, and they won't be around for the bust ( or no one will remember who's at fault). In the long run, cheap credit leads to too much debt and people can borrow no more. This leads to two choices. Choice one, the borrowing must stop, and with it consumption. This sends the economy into recession or depression ( this is heroin withdrawal, the Volcker strategy in the 1980's). Or two, the government must make credit even cheaper ( higher doses of heroin - the Alan Greenspan strategy in 2001).