Probably mainly caused by Economic Transition.
Friedman and Schwartz's interpretation of the GreatDepression is both figuratively and literally at the heart of their book. The detailed discussion occupies about 30 percent of the total, and the episode is referred to by way of contrast in discussions of other episodes. Princeton University Press later issued this section as a separate volume, The Great Contraction.
in 1963, he and Anna Schwartz coauthored Monetary History of the United States, 1867-1960. In it they contend that the GreatDepression was the result of ill-conceived monetary policies by the Federal Reserve. Upon receipt of the unpublished manuscript submitted by the authors, the Federal Reserve board responded internally with a lengthy critical review. Such was their agitation that the Fed governors discontinued their policy of releasing minutes from the board's meetings to the public. Additionally, they commissioned a counterhistory to be written (by Elmus R Wicker) in the hope of detracting from Monetary History.
sample chapter. To some extent the proponents of these two views argued past each other, with monetarists stressing the monetary sources of the latter stages of the Great Contraction (from late 1930 or early 1931 until 1933), and antimonetarists emphasizing the likely importance of nonmonetary factors in the initial downturn... Substantively - in marked contrast to the inconclusive state of affairs that prevailed in the late 1970s - the new Gold Standard research allows us to assert with considerable confidence that monetary factors played an important causal role, both in the worldwide decline in prices and output and in their eventual recovery.
Murray Rothbard: America's GreatDepression http://mises.org/rothbard/agd http://en.wikipedia.org/wiki/America%27s_Great_Depression focuses on causes (Government Failure), not solutions.