The length of US business expansions: When did the break in the data occur?

It is generally accepted that US business expansions have been longer and contractions shorter since the end of World War II. Previous tests of this proposition uniformly assume that the change in business-cycle behavior occurred after the war. This paper presents evidence that it is more likely that business-cycle expansions became longer beginning with the March 1933 expansion, a date which coincides with the US leaving the gold standard. The results are robust to consideration of the alternative business-cycle chronology of Romer [Remeasuring business cycles. Journal of Economic History 54 (1994) 573-609]. Within the set of post-1933 expansions, we find evidence of a secondary break beginning with the 1982 expansion.