Unemployment Continued

Jon pretty much nailed almost everything you need to know about employement/unemployment statistics.  I'll try to add a just little more context.  First, there is a methodology which is part of the establishment survey called the "birth/death model".  It is not what it sounds like, however.  You see, a big part of the jobs created or lost each month comes from the creation of new businesses or the closing of old ones.  The survey can only gauge such activity with a considerable lag, because new jobs and old lost jobs are not yet added to the unemployment insurance rolls.  To fix this, the Bureau of Labor Statistics (BLS) must estimate how many new business "births" are created and likewise "deaths".   They base the calculation on actual birth/death statistics, but naturally these reflect what happened in the past and now what is happening now. so they tend to be way off the mark during turning points in the economy- overstating employment when the economy slows and understating new employment when the economy picks up.