Causes of the Great Depression
Second, there are the monetarists, who believe that the Great Depression started as an ordinary recession, but that significant policy mistakes by monetary authorities (especially the Federal Reserve) caused a shrinking of the money supply which greatly exacerbated the economic situation, causing a recession to descend into the Great Depression. Related to this explanation are those who point to debt deflation causing those who borrow to owe ever more in real terms.
Causes of the Great Depression
Fisher's debt-deflation theory initially lacked mainstream influence because of the counter-argument that debt-deflation represented no more than a redistribution from one group (debtors) to another (creditors). Pure re-distributions should have no significant macroeconomic effects.