For the fifth successive month the Bureau of Labor Statistics (BLS) household survey showed sizeable employment gains, gains that were fast enough to reduce the unemployment rate to 8.5%. Revisions in seasonal adjustment changed the timing of the unemployment-rate decline over the past few months. There can be little doubt, however, that the household survey shows a faster rate of job growth than the one needed to keep up with the growth in the population. Since July the fraction of adults who report holding a job has increased 0.3 percentage points. To be sure, the gains have been modest compared with the drop in the employment-to-population rate caused by the Great Recession. (Between December 2007 and July 2011 the adult employment rate fell a total of 4.5 percentage points.) Still, the employment picture is much brighter in December than it seemed in July.
http://www.brookings.edu/up-front/posts/2012/01/06-jobs-report-burtless