The U.S. unemployment rate dropped in November to 4.6%, the lowest level since August 2007. 

This is certainly good news, but perhaps not as positive as it first appears.  Part of the reason why the unemployment rate dropped last month is due to 178,000 new jobs added in the economy - not a trivial number.  In fact, as Justin Wolfers notes, this is 178 times the number of Carrier jobs that were recently "rescued." 

But a second reason the unemployment rate dropped is due to a decline in labor force participation.  In November, the U.S. labor force dropped by 226,000 workers, bringing the labor force participation rate (LFPR) down to 62.7 percent.  This is the third straight drop in the LFPR after showing signs of improvement this year with a 63% in March.