The Development and Role of the National Bureau's Business Cycle Chronologies

A working definition, first formulated in the 1920's by Mitchell and revised in the 1940's, has been in use at the National Bureau for over fifty years and is still employed to identify and date business cycles. The NBER historical chronologies for England, France, and Germany as well as the United States have been intensively in economic research and are widely accepted. The U.S. chronology, which is being updated as promptly as the data allow, also have the important practical function of aiding the analysis of current business conditions and forecasting near-term cyclical developments. This paper discusses the main aspects of the NBER concept of business cycles; the early views and developments bearing on the construction of the chronologies; the problems and procedures involved; the characteristics and dependability of the historical reference dates; and the National Bureau's work in this field since World War II. Some recent uses of the U.S. dates to measure the duration, amplitudes, and diffusion of business expansions and contractions are illustrated. Finally, we show and discuss chronologies of growth cycles,' i.e., trend-adjusted business cycles, for 13 countries in the post-World War II period.