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The American Community Survey: Accuracy and Timeliness Issues

GAO-02-956R Published: Sep 30, 2002. Publicly Released: Oct 30, 2002.
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Highlights

GAO has reviewed several major issues associated with the proposed full implementation of the American Community Survey (ACS) by the Bureau of the Census for 2003. If the ACS is approved, this mandatory mail survey would cost from $120 to $150 million a year, and would require responses from a sample of 3 million households to some 60 to 70 questions. The ACS would replace the decennial census long form for 2010 and subsequent decennial censuses. On the basis of sampling errors and related measures of reliability, the Census Bureau has decided that ACS data will be published annually for geographic areas with a population of over 65,000; as 3-year averages for geographic areas with a population of 20,000 to 65,000; and as 5-year averages for geographic areas with a population of less than 20,000. According to the Bureau, the annual ACS data and 3-year averages would be significantly less accurate than data for 2010 from the decennial census long form; 5-year averages, which would be available at the detailed long-form level of geographic detail, would be about as accurate as the long-form data. Federal agencies that extensively use the 2000 Decennial Census long-form data for program implementation would use ACS data in the future if the long form was eliminated. The questions to be asked in the 2003 ACS reflect justifications--specific statutes, regulations, and court cases--provided to the Bureau by federal agencies. To identify these justifications, the Bureau worked with the agencies using a process similar to that used to prepare the justifications for the questions on the 2000 Decennial Census long form. The Bureau's plan to use responses to ACS questions to develop samples for additional surveys is not prohibited by the disclosure provisions in 13 U.S.C. 9, as long as the Bureau conducts the surveys. Some ACS questions duplicated or are similar to questions on two existing federal surveys. Identical questions could be eliminated from the existing surveys because the ACS data would be more accurate, available at greater geographic detail, and more timely. Similar questions could be eliminated if the greater ACS accuracy, detail, and timelines offset the advantage of asking additional and more relevant questions on these surveys. The Bureau determined, and GAO has agreed in a recently issued legal opinion, that it has the statutory authority to conduct the ACS as a mandatory survey, like the decennial census long form the ACS would replace. If the ACS was conducted as a voluntary survey, the Bureau would need to make up for the lower mail response with more interviews to maintain the proposed level of accuracy of the ACS. Because obtaining responses by interview is more costly than obtaining responses by mail, conducting the ACS as a voluntary survey would be more expensive. The Bureau used a number of strategies to encourage participation in the ACS test program, which started in 1996. Two of the key strategies were (1) the training of interviewers, whose job it was to collect data from households that did not return the mail questionnaires, and (2) outreach and promotion efforts. Telephone and in-person interviewers were provided scripted replies, designed to overcome the objections of nonrespondents, that highlighted themes such as the importance of ACS data to the community and the legal requirement to participate in the ACS. Since 1997, outreach and promotion efforts have increased to include local workshops and town hall meetings, as well as contacts with representatives of print and broadcast media, professional journals, and umbrella organizations.

Recommendations

Recommendations for Executive Action

Agency Affected Recommendation Status
Department of Commerce In order to facilitate the transition by federal agencies form the use of 2000 Decennial Census data to the ACS, the Secretary of Commerce should direct the Director, Bureau of the Census, to revise and expand the quality-testing and evaluation component of the ACS development program. In particular, the Secretary of Commerce should direct the Director of the Census Bureau to establish a process to make sure that the ACS development program produces key information needed by federal agencies that will have to use ACS data when the long form is eliminated.
Closed – Implemented
In a letter dated 9/1/05, the Census Bureau reported that this recommendation has been implemented.
Department of Commerce In order to facilitate the transition by federal agencies from the use of 2000 Decennial Census data to the ACS, the Secretary of Commerce should direct the Director, Bureau of Census, to revise and expand the quality-testing and evaluation component of the ACS development program. In particular, the Secretary of Commerce should direct the Director of the Census Bureau to develop estimates, for states and large local government areas, of social, economic, and housing characteristics from the 2000-02 ACS special surveys and the 2003 and 2004 ACS to provide agencies with ACS estimates that are conceptually consistent with the 2000 Census.
Closed – Not Implemented
In commenting on a draft of this report, the Bureau agreed with the thrust of GAO's recommendations. However, it expressed a number of concerns about some of the detailed findings.
Department of Commerce In order to facilitate the transition by federal agencies from the use of 2000 Decennial Census data to the ACS, the Secretary of Commerce should direct the Director, Bureau of the Census, to revise and expand the quality-testing and evaluation component of the ACS development program. In particular, the Secretary of Commerce should direct the Director of the Census Bureau to expand the planned evaluation of differences between data from the Census 2000 Supplementary Survey and the 2000 Decennial Census long form, so as to identify techniques for agencies to use to improve consistency between the 2000 Census data and the 2003 and subsequent ACS data.
Closed – Not Implemented
In commenting on a draft of this report, the Bureau agreed with the thrust of GAO's recommendations. However, it expressed a number of concerns about some of the detailed findings.
Department of Commerce In order to facilitate the transition by federal agencies from the use of 2000 Decennial Census data to the ACS, the Secretary of Commerce should direct the Director, Bureau of Census, to revise and expand the quality-testing and evaluation component of the ACS development program. In particular, the Secretary of Commerce should direct the Director of the Census Bureau to analyze and report on differences between year-to-year changes for 2001 and 2002, using the data--from ACS special supplements and the Current Population Survey at the national and state levels--for key economic and housing characteristics, such as the unemployment and poverty rates, to determine the stability of the annual ACS data.
Closed – Not Implemented
In commenting on a draft of this report, the Bureau agreed with the thrust of GAO's recommendations. However, it expressed a number of concerns about some of the detailed findings.
Department of Commerce In order to facilitate the transition by federal agencies from the use of 2000 Decennial Census data to the ACS, the Secretary of Commerce should direct the Director, Bureau of the Census, to revise and expand the quality-testing and evaluation component of the ACS development program. In particular, the Secretary of Commerce should direct the Director of the Census Bureau to extend the scope of the ACS development program to include plans to benchmark ACS estimates, beginning with 2005, to the 2010 Census population counts and the revised 2005-09 population estimates to ensure comparability between the ACS and 2010 Census data.
Closed – Not Implemented
In commenting on a draft of this report, the Bureau agreed with the thrust of GAO's recommendations. However, it expressed a number of concerns about some of the detailed findings.
U.S. Census Bureau To more completely address the possibility of reducing the reporting burden in existing surveys, the Secretary of Commerce should direct the Director, Bureau of the Census, to review for possible elimination, proposed ACS questions now asked on two surveys conducted by the Bureau--the annual demographic supplement of the Current Population Survey and the American Housing Survey.
Closed – Not Implemented
In commenting on a draft of this report, the Bureau agreed with the thrust of GAO's recommendations. However, it expressed a number of concerns about some of the detailed findings.

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