How the Government Measures Unemployment
(page 13 - 14)
While the UI claims data provide useful information, they are not used to measure total unemployment because they exclude several important groups. To begin with, not all
workers are covered by UI programs. For example, self-employed workers, unpaid family workers, workers in certain not-for-profit organizations, and several other small (primarily seasonal) worker categories are not covered.
In addition,
the insured unemployed exclude the following:
1. Unemployed workers who have exhausted their benefits.
2. Unemployed workers who have not yet earned benefit rights (such as new entrants or reentrants to the labor force).
3. Disqualified workers whose unemployment is considered to have resulted from their own actions rather than from economic conditions; for example, a worker fired for misconduct on the job.
4. Otherwise eligible unemployed persons who do not file for benefits.
Because of these and other limitations, statistics on insured unemployment cannot be used as a measure of total unemployment in the United States. Indeed, over the past decade, only about one-third of the total unemployed, on average, received regular UI benefits.
SOURCE:
http://www.bls.gov/cps/cps_htgm.pdf