經濟大蕭條（Great Depression）

關於美國的經濟大蕭條（Great Depression）的起因，諾貝爾經濟學獎得主保羅．克魯曼（Paul Krugman）在他寫《面對失靈的年代：克魯曼談金融海嘯》（The Return of Depression Economics and the Crisis of 2008）一書，有這樣的解釋：

Nowadays practically the whole spectrum of economists, from Milton Friedman leftward, agrees that the Great Depression was brought on by a collapse of effective demand and that the Federal Reserve should have fought the slump with large injections of money.