The Oil Shock of the 1930s: Another Factor?
The chart above shows the real monthly price of oil from January 1931 to December 1939, using monthly oil prices adjusted for inflation using monthly CPI data, both data series from Global Financial Data (paid subscription required). Between 1931 and 1934, real oil prices more than doubled from $20 to $40 (in 2008 dollars), and peaked at $42.59 by the summer of 1937. The oil shock of the early 1930s was roughly equivalent to the oil shock that resulted in a doubling of oil prices between 1979 and 1981, contributing to an 18-month recession and 10.8% unemployment.
Along with contractionary fiscal policy via tax hikes, contractionary monetary policy, and huge increases in tariffs and trade protection, perhaps it was also the "energy shock of the 1930s" that helped turned what would have been a fairly ordinary recession into the Great Depression?