New in paperback. Hardcover was published in 2009. Posner analyzes the two basic remedial approaches to the crisis, which correspond to the two theories of the cause of the Great Depression: the monetarist - that the Federal Reserve Board allowed the money supply to shrink, thus failing to prevent a disastrous deflation - and the Keynesian - that the depression was the product of a credit binge in the 1920's, a stock-market crash, and the ensuing downward spiral in economic activity.