Here are the BLS names and definitions of these six unemployment rates:
U1. Persons unemployed 15 weeks or longer as a percentage of the civilian labor force.
U2. Job losers and persons who have completed temporary jobs, as a percent of the civilian labor force.
U3. Total unemployed, as a percent of the civilian labor force. This is the Official Unemployment Rate that is reported monthly in the media.
U4. Total unemployment plus discouraged workers, as a percent of the civilian labor force plus discouraged workers.
U5. Total unemployed, plus discouraged workers, plus all other marginally attached workers, as a percent of the civilian labor force plus all marginally attached workers.
U6. Total unemployed, plus all marginally attached workers, plus total employed part time for economic reasons, as a percent of the civilian labor force plus all marginally attached workers.
What makes these different rates different?
The short answer is that they measure different things for different purposes. Obviously, all of these measures are percentage measures. They are calculated by dividing some number (the numerator) by some other number (the denominator).
The denominator turns out to be the same for rates U1, U2, and U3; it's the civilian labor force, which includes all civilians who are employed (even just barely), plus unemployed people who are actively looking for jobs. But the denominators in measures U4, U5, and U6 keep getting bigger and bigger because each measure includes additional groups of jobless - or underemployed - people than the measure just before it.
The numerator is different for every one of these measures. The numerator of U1, for example, includes only the long-term unemployed (i.e., folks who have been unemployed for 15 weeks or longer). The official unemployment rate, U3, includes all unemployed persons who are actively seeking work. This most-often-cited measure of unemployment has often been criticized on the grounds that it understates the true extent of workforce underutilization - because it ignores people who are so discouraged that they have quit looking for work and part-timers who would prefer to be employed full time.
Measures U4, U5 and U6 were developed to meet the criticisms leveled at U3, the official rate. The rate that measures the broadest group of underutilized workers is, of course, U6. The numerator includes just everybody who isn't working as much as they would like. So, if you want a measure that tells the grimmest story that can be told, then U6 is the measure for you.
So, what's the state of the national employment situation according to these six measures?
This also doesn't take into effect that the percentage of people seeking work has dropped by half a percent or so in the calculations; it doesn't take into effect our added prison population, it doesn't take into effect those on Disability.
Cycloptichorn