U.S. Census Bureau

Fact Sheet


Differences between the Income and Poverty Estimates from the American Community Survey and the Annual Social and Economic Supplement to the Current Population Survey


August 19, 2004


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:



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. Provide timely estimates of income, as well as official poverty estimates


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 addresses 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 a person 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 their place of usual residence (where they spend 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 their 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).

Time Period Covered

Monthly interviews conducted January to December 2003 asked about income in the previous 12-month period, yielding a total time span covered by responses of 23 months. The survey’s 12-month estimates are centered on December 15, 2002.

Monthly interviews conducted from February to April 2004 ask about calendar year 2003 income. The survey’s 12-month estimates are centered on July 1, 2003.

Length and Detail of Questions

Using a series of eight questions, the ACS asks about money income, plus one type of noncash benefit (food stamps) during the previous 12 months.

CPS asks a series of questions about more than 50 sources of income, including questions about the amount of several noncash benefits such as food stamps and employment-related health insurance, during the previous calendar year.

Inflation Adjustment

All dollar values for income are adjusted to latest calendar year of estimates using the Consumer Price Index for the date collected versus the average for the year.



Source: U.S. Census Bureau

Contact the Demographic Call Center Staff at 301-763-2422 or 1-866-758-1060 (toll free) or visit ask.census.gov for further information on Income Data.

Source: U.S. Census Bureau, Housing and Household Economic Statistics Division
Last Revised: December 20, 2005