Causes of the Great Depression
In their 1963 book "A Monetary History of the United States, 1867–1960", Milton Friedman and Anna Schwartz laid out their case for a different explanation of the Great Depression. Essentially, the Great Depression, in their view, was caused by the fall of the money supply. Friedman and Schwartz write: "From the cyclical peak in August 1929 to a cyclical trough in March 1933, the stock of money fell by over a third." The result was what Friedman and Schwartz called "The Great Contraction" — a period of falling income, prices, and employment caused by the choking effects of a restricted money supply. Friedman and Schwartz argue that people wanted to hold more money than the Federal Reserve was supplying. As a result, people hoarded money by consuming less. This caused a contraction in employment and production since prices were not flexible enough to immediately fall. The Fed's failure was in not realizing what was happening and not taking corrective action. In a speech honoring Friedman and Schwartz, Ben Bernanke stated:
Causes of the Great Recession
Excessive consumer housing debt was in turn caused by the mortgage-backed security, credit default swap, and collateralized debt obligation sub-sectors of the finance industry, which were offering irrationally low interest rates and irrationally high levels of approval to subprime mortgage consumers because they were calculating aggregate risk using gaussian copula formulas that strictly assumed the independence of individual component mortgages, when in fact the credit-worthiness almost every new subprime mortgage was highly correlated with that of any other because of linkages through consumer spending levels which fell sharply when property values began to fall during the initial wave of mortgage defaults. Debt consumers were acting in their rational self-interest, because they were unable to audit the finance industry's opaque faulty risk pricing methodology.