The data represents the length of each recession since WWII. The source is the NBER. I downloaded the dates from the FRED data base. From the data, it appears that recessions don't last very long. I don't say that this proves the classical economists wrong or supports Keynesians, but only point out that the fluctuations seem to be short term. Also past behavior of recessions does not predict future as the recessions don't have a memory. The data suggests that the length of the recession might not be as protracted as politicians are suggesting to pass the stimulus package.