(November/December 2000) Until Census 2000 data are released, the 1990 Census is the official picture of our nation’s people and housing. Before 2010, the U.S. Census Bureau plans to update the picture that emerges from the 2000 census with an ongoing American Community Survey “video.”

The American Community Survey (ACS) is slotted to replace the decennial census long form by collecting essentially the same information throughout the decade rather than once every 10 years. With updated information, researchers will be able to track changes over time and measure relative differences among population groups and areas.

The Census Bureau has been developing the ACS since 1996, when it was tested in just four sites. The ACS has since expanded to 31 diverse sites, collecting data that can be compared with Census 2000 results. These comparisons are laying the groundwork for the transition from the long form to the ACS. The plan is to fully implement the survey in 2003 and continue data collection every year thereafter.

Tracking Trends with the ACS

The American Community Survey provides planners in Fulton County, Pa., with updated information about the number and location of poor children in the county.

Percent of children in poverty, by minor civil division as a percent of related children under age 18, 1996

Source: Prepared by the Geography Division, U.S. Census Bureau.

The basic design of the survey is self-enumeration through mail-out and mail-back operations in every county to a representative sample of about 3 million addresses (households and group quarters) across the country. The questions are essentially the same as those on the decennial census long form. Follow-up of those who do not mail back their forms is conducted first by telephone and then through face-to-face interviews with one-third of the remaining nonrespondents.

The results have been encouraging. Effective final response rates for the ACS have been about 97 percent, even during the Census 2000 period, when response rates for the census long form dropped. ACS field staff work full-time in their areas and can explain to local communities how the ACS benefits them. Because of this, the ACS has not encountered the kind of resistance from respondents that the census long form has engendered.

Since 1996, Census Bureau staff have been meeting with users of the decennial census long form to ensure that the new survey will meet their needs. Among these is a need for reliable data on small areas. The ACS accumulates samples for small areas such as rural areas and census tracts (statistical subdivisions of counties) over multiple years to provide data quality similar to that obtained from the long form. For areas with fewer than 20,000 people, collecting a sufficient sample to provide reliable data will take five years. The first such data release is planned for 2008, and the five-year “moving averages” will be updated every year thereafter to provide, for the first time, the ability to track trends for small areas. Data users have testified to Congress that such updated multiyear averages will show general trends that are more valuable than out-of-date long-form data.

Information updated every year also will open new possibilities for using data. Researchers are considering how the updated trends provided by the ACS can be used to improve needs assessment, predictive models, and estimates of characteristics such as disability and poverty. Geographic Information Systems (GIS) can use the current population and housing information to help community officials monitor and evaluate programs.

As an ongoing survey, the ACS is a flexible vehicle, capable of adapting to changing customer needs. Once it is fully implemented, it can be expanded to accommodate questions of national policy interest and even specialized supplements to help identify the characteristics of special population groups.

Editor’s Note: The Census Bureau plans to replace the long form with the American Community Survey, but the decision to do so rests with Congress. Congress decides annually whether to allocate the funding needed to conduct the survey, and will continue to do so after the survey is fully implemented in 2003. The Census Bureau is conducting research to ensure that it and Congress will have the information they need to make final plans for the design of the 2010 census; survey design and questionnaire content are guided by the needs of Congress, federal agencies, and other data users.

Cynthia Taeuber is a program policy adviser for the American Community Survey at the U.S. Census Bureau and the University of Baltimore.

For More Information

Detailed information about the ACS is available on the Census Bureau’s website at www.census.gov/acs/www/.

Multiple years of data for the current sites are available through the American FactFinder at http://factfinder.census.gov and on a free CD-ROM (request by calling 888/456-7215 or by sending an e-mail to acs@census.gov).