Much of the current population data is derived from the Current Population Survey (CPS), which is a sample household survey of the noninstitutional civilian population in the United States. Its primary task is to produce monthly statistics on unemployment and the labor force, which are published by the U.S. Bureau of Labor Statistics in its monthly bulletin Employment and Earnings. Much of the data collected is also available at the CPS Internet Site.
The CPS also serves as a vehicle for supplemental studies on subjects other than employment, such as tobacco use and marital and birth history.
The data from CPS are available in reports and microdata files. From the basic and supplemental data, the Census Bureau issues three report series:
The Survey of Income and Program Participation (SIPP) is a sample household survey of the noninstitutional population in the United States conducted by the Census Bureau. The survey collects data from the same household over time, usually for 32 months. The survey's principal purpose is to provide estimates of money and in-kind income and participation in government programs. Recurrent questions focus on employment, types of income, and noncash benefits. Periodically, the survey also includes questions on other topics, such as assets and liability, disability, and child care. From time to time, special supplemental questions are also asked.
The data from SIPP are available in reports are available in reports and microdata files. Much of the data collected is available at the SIPP Internet Site. The report series is: P70, Household Economic Studies
The Census Bureau updates the population figures from the decennial census of population and housing by issuing estimates in intervening years. The methods employed to make these estimates include the use of administrative records, such as those maintained by the U.S. Social Security Administration and the National Center for Health Statistics.
The Census Bureau also issues population projections. In large part, these projections are made by the use of statistical methods.
These population estimates and projections are available in reports and data files. The data files are available at the Census Bureau internet site under the Estimates and Projections areas. The report series is: P25, Population Estimates and Projections.