When fully implemented, the American Community Survey (ACS) will be the largest household survey in the United States. Like the decennial census long form it is designed to replace, the ACS provides labor force estimates for small geographic areas - most cities, counties, and metropolitan areas of 250,000 or more during the testing phase, and, beginning in 2010, the ACS will use multi-year averages to provide estimates for all areas down to census tracts/block groups. Estimates for the nation and states are also available. All ACS estimates are updated annually.
Because of its detailed questionnaire and its experienced interviewing staff, the Current Population Survey (CPS) Annual Social and Economic Supplement (ASEC) is a high quality source of information used to produce the official annual estimate of poverty, and estimates of a number of other socioeconomic and demographic characteristics, including income, health insurance coverage, school enrollment, marital status, and family structure.
The following chart summarizes the key differences between the ACS and the CPS:
|Topic||American Community Survey||Current Population Survey|
|Principal Purpose||Replace decennial census long form by providing annual (or multi-year average) estimates of selected social, economic, and housing characteristics of the population for many geographic areas and subpopulations.||Produce specific socioeconomic and demographic estimates for the United States, and estimates for states for selected characteristics and subpopulations.|
|Geography||Nation, states, and cities and counties of 250,000 or more. Eventually, areas as small as census tracts using multi-year averages.||Nation, regions, and states for selected characteristics.|
|Sample Size||About 800,000 addresses per year during the testing phase (2000-2004); about 3 million housing units per year when fully implemented (planned for 2005). Data are collected from about one-twelfth of the sample each month.||Annual sample size is about 100,000 addresses.|
|Data Collection Method||Mail, telephone, and personal-visit interviews for the 50 states and the District of Columbia. About half the responses are obtained by mail. When fully implemented, the ACS will include Puerto Rico. The ACS is a mandatory survey.||Telephone and personal-visit interviews for the 50 states and the District of Columbia. The CPS is a voluntary survey.|
|Residency Status||The ACS includes people at the address where they are at the time of the survey if they have been there, or will be there, more than 2 months, whether or not they have a "usual residence elsewhere."||The CPS sample unit’s householder (one of the people in whose name the unit is rented or owned) must consider the unit to be his or her place of usual residence (where he or she spends most of the time during the year) to be counted as an occupied unit, which is traditional in most censuses and housing surveys. If a family has more than one home, the interviewer has to determine if the sample unit is its usual residence.|
|Population Universe||The testing phase of the ACS includes the household population. This universe includes both the civilian and military population in households and excludes the group quarters population. When fully implemented, the ACS will include both the household and the group quarters populations (that is, the resident population). The group quarters population consists of the institutionalized (such as people in correctional institutions or nursing homes) and the noninstitutionalized (most of whom are in college dormitories). The weighting is controlled to population estimates as of July 1 (e.g., July 1, 2003 for the 2003 ACS).||The CPS includes the civilian noninstitutionalized population. This universe includes civilians in households, people in noninstitutional group quarters (other than military barracks) and military in households living off post or with their families on post (as long as at least one household member is a civilian adult). The universe excludes other military in households and in group quarters (barracks), and people living in institutions. The weighting is controlled to population estimates as of March 1 (e.g., March 1, 2004 for the 2004 CPS ASEC).|
|Question Detail||The ACS asks if the person lived in the same house or apartment 1 year ago. If the respondent indicates that he or she did not live in the same house or apartment 1 year ago, then the city, town or post office, along with the county, state, and zip code of their residence 1 year ago, is requested. The respondent is also asked if he or she lived inside the city or town limits. ACS collects data every month and asks about residence one year earlier without referencing a specific date.||The CPS also asks if the person lived in the same house or apartment 1 year ago. If the respondent indicates that he or she did not live in the same house or apartment 1 year ago, then the city, town or post office, along with the county, state, and zip code of their residence 1 year ago, is requested. The respondent is also asked if he or she lived inside the city or town limits. Prior to 2004 the CPS referenced a specific date, March 1st of the prior year. From 2004, the reference date of March 1st will be replaced with a reference to ‘one-year ago’.|