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. For instance, beginning in 1994, the CPS estimates reflect the results of a major redesign of the survey. (For more information on the CPS redesign, see Chapter 1, "
Labor Force Data Derived from the Current Population Survey," in the BLS
Handbook of Methods.)
There are about 60,000 households in the sample for this survey. This translates into approximately 110,000 individuals, a large sample compared to public opinion surveys which usually cover fewer than 2,000 people. The CPS sample is selected so as to be representative of the entire population of the United States. In order to select the sample, all of the counties and county-equivalent cities in the country first are grouped into 2,025 geographic areas (sampling units). The Census Bureau then designs and selects a sample consisting of 824 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. (For a detailed explanation of CPS sampling methodology, see
Chapter 1, of the BLS
Handbook of Methods.)