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How these figures are counted is a bit more complicated, but here's the official line.

http://www.bls.gov/cps/cps_htgm.htm

Because unemployment insurance records relate only to persons who have applied for such benefits, and since it is impractical to actually count every unemployed person each month, the Government conducts a monthly sample survey called the Current Population Survey (CPS) to measure the extent of unemployment in the country. The CPS has been conducted in the United States every month since 1940 when it began as a Work Projects Administration project. It has been expanded and modified several times since then. As explained later, the CPS estimates, beginning in 1994, reflect the results of a major redesign of the survey.

There are about 60,000 households in the sample for this survey. The sample is selected so as to be representative of the entire population of the United States. In order to select the sample, first, the 3,141 counties and county-equivalent cities in the country are grouped into 1,973 geographic areas. The Bureau of the Census then designs and selects a sample consisting of 754 of these geographic areas to represent each State and the District of Columbia. The sample is a State-based design and reflects urban and rural areas, different types of industrial and farming areas, and the major geographic divisions of each State.

Each of the 754 areas in the sample is subdivided into enumeration districts of about 300 households. The enumeration districts, in turn, are divided into smaller clusters of about four dwelling units each, through the use of address lists, detailed maps, and other sources. Then, the clusters to be surveyed are chosen statistically, and the households in these clusters are interviewed.