Close your books and take out a pencil and a sheet of paper for a one-question multiple-choice exam:

Over the 108 years since the beginning of the 20th century, what percentage of the time has the United States been in recession?

     A) 5%
     B) 10%
     C) 20%
     D) 25%

The sad reality is that "D" gets you an "A" on this exam. In fact, if you measure from 1871, the date of earliest S&P Composite data featured on this website, the number jumps to 30% (the last three decades of the 19th century were rather grim).

The good news, however, is evident in the accompanying chart, which shows all the recessions since 1871 as defined by the National Bureau of Economic Research (NBER). During those 137 years, the United States has been in recession 30% of the time. Fortunately the economic conditions have gradually improved over this time frame:

• 1871-1900: Recessions = 48% of the time
• 1900-1950: Recessions = 37% of the time
• 1950-2009: Recessions = 13% of the time

The current recession is in its 19th month — the longest since the Great Depression.

Or is it? We won't really know until the NBER makes the call on when this recession ends. That can be a year or more after the date they officially select. Who knows? They may decide the recession ended a few months ago!