The Decennial Census is a major source of detailed population information, and the benchmark for estimation from almost all other data sets. It is a comprehensive source of information on individuals economic and social characteristics in local areas across the country. The short form is conducted primarily as a mail-out, mail-back survey to every household in the United States and is the basis on which seats in Congress are apportioned. It asks only name, sex, age, race/Hispanic origin, relationship, and whether the household owns or rents its housing The long form is sent to a sample of the population (17 percent in 2000) and forms the basis for social and economic information published by the Census Bureau. The long form includes questions on marital status, education, ancestry, migration, employment, income, welfare receipt, and housing conditions. New in 2000 is a question required by PRWORA, on grandparents as caregivers for children. The census is conducted every 10 years.
Web site: http://www.census.gov/dmd/www/2khome.htm
The American Community Survey (ACS) is a new approach under development by the U.S. Census Bureau for collecting accurate, timely information needed for critical government functions. The ACS instrument is based on the Decennial Census long form. If fully implemented, this new data collection approach will provide data users with timely demographic, housing, social, and economic data updated every year that can be compared across states, communities, and population groups. In addition, the ACS is a flexible data collection method with the ability to adapt to changing data needs; for example, the potential exists for adding questions of national policy interest or specialized supplements in the future. With the American Community Survey, data will be available every year for all states, as well as for all cities, counties, metropolitan areas, and population groups of 65,000 people or more. For smaller areas, it will take two to five years to accumulate a sufficient sample to produce data for areas as small as census tracts. For example, for areas of 20,000 to 30,000, data can be averaged over three years. For rural areas and city neighborhoods or population groups of less than 15,000 people, it will take five years to accumulate an adequate sample size.
Web site: http://www.census.gov/acs/www/
The Current Population Survey (CPS) has been conducted monthly by the Bureau of the Census since 1942. Its main purpose is to provide estimates for employment, unemployment, and other characteristics of the labor force. The survey focuses on individuals aged 15 and older, but since 1979 limited demographic data have been collected on children in the sample. In addition to the core monthly survey, the CPS also collects annual data in the March Supplement on prior year work experience, education, income (including welfare receipt and program participation), and migration. Other supplements focus on such topics as school enrollment, child support and alimony, and fertility. The CPS is a probability based sample, with a total sample size of about 71,000 households per month (50,000 to 57,000 are actually interviewed). The sample is representative at both the state and the national level. However, the small sample size for many states restricts its usefulness as a source of annual data on state performance, as the standard errors of the state estimates for a single year are quite large. Various small area estimation techniques are currently used by the Census Bureau and others to produce reliable state-by-state estimates, including combining and averaging three or four years of data.
The Survey of Income and Program Participation (SIPP) is a continuous series of national panels begun in 1983 by the Census Bureau. The SIPP content is built around a core of labor force, program participation, and income questions designed to measure the economic situation of persons in the United States. Panel members are asked the core questions every four months, and are asked to recall their activities over the four previous months. In each wave of interviews, a set of modules on topics not covered in the core section are also asked. Topics covered by the modules include personal history, child care, wealth, program eligibility, child support, disability, school enrollment, and taxes. Until recently, the SIPP consisted of overlapping panels, with a new panel of 14,000 to 20,000 households introduced each February (through 1993) and interviewed for a total of 2 ½ years. Starting in 1996, the SIPP panels have been expanded in both size (to about 36,000 households) and duration (to 4 years in 1996, 3 years thereafter), but a new panel will only be drawn every 4 years. The redesigned SIPP includes enhanced questions about receipt of government program benefits, including reasons why receipt was begun or ended, and which household members were covered.
The Survey of Program Dynamics (SPD) was created specifically for the Census Bureau to track the effects of PRWORA using a "pre-post" comparison. Starting with SIPP respondents first interviewed in 1992 and 1993, the SPD is a longitudinal survey with data from annual retrospective interviews conducted each year between 1997 and 2002. Combined with SIPP data collected from the 1992 and 1993 panels, the SPD will provide longitudinal panel data on approximately 18,500 households for 10 years. The survey primarily focuses on employment and earnings, income, and program participation, and also includes questions on child well-being and adolescent behaviors.
The Panel Study of Income Dynamics (PSID) is designed to study the determinants of changes in the economic well-being of families and individuals across time and generations. The survey, conducted by the University of Michigan, is based on a probability sample of about 5,000 U.S. households first interviewed in 1968. The individuals in these households are interviewed through the years, regardless of whether they remain in the same household. For example, children are followed as they advance through childhood and into adulthood, forming family units of their own. Although the original design over-sampled lower income and minority households, the sample also included a complete representative sample of families at all income levels. Surveys were conducted annually through 1997, then switched to every other year for cost reasons. While the sample size is smaller than most other national data sets, the data collected are extremely rich. The survey emphasizes the dynamic aspects of economic and demographic behavior, but covers a broad range of topics including: employment, income, wealth, housing, food expenditures, transfer income, and marital and fertility behavior.
Web site: http://www.isr.umich.edu/src/psid/
The National Longitudinal Surveys (NLS) of Labor Market Experience are a collection of panel surveys sponsored by the Department of Labor. The primary focus in these surveys is on education and labor market transitions; however, all these surveys feature a comprehensive set of questions about family relationships, income, welfare receipt and numerous other subjects. Starting in the mid-1960s, four groups were surveyed: young men (aged 14-24 in 1966), older men (aged 45-59 in 1966), young women (aged 14-24 in 1968) and mature women (aged 30-44 in 1967). The first two groups were last interviewed in 1981 and 1990 respectively, while the other two groups are still being interviewed. Another youth (both young men and young women) survey (NLSY79) was begun in 1979 and, starting in 1986, supplemental information was collected on the children born to the young women in this panel. A new youth survey (NLSY97) was begun in 1997. A key feature of the NLSY is that all respondents were asked to take the Armed Services Vocational Aptitude Battery, a high-quality test of academic and non-academic knowledge and skills.
Web site: http://stats.bls.gov/nlshome.htm