The unemployment rate is the share of the labor force that is jobless, expressed as a percentage. It is a lagging indicator, meaning that it generally rises or falls in the wake of changing economic conditions, rather than anticipating them. When the economy is in poor shape and jobs are scarce, the unemployment rate can be expected to rise. When the economy is growing at a healthy rate and jobs are relatively plentiful, it can be expected to fall.
In the U.S., the U3 or U-3 rate, which the Bureau of Labor Statistics (BLS) releases as part of its monthly employment situation report, is the most commonly cited national rate. It is not the only metric available, however, and it receives criticism for giving the impression that the labor market is healthier than alternative measures would indicate.
The official unemployment rate is known as U3.