to census respondent, and housing tenure (renter/owner), while the long form administered to roughly one-sixth of households added about 62 items, 36 of them pertinent to demographic and economic characteristics and 26 related to housing.

Fifty years after the development of separate short and long forms in the census, the Census Bureau proposes to make another change in the collection of population characteristics data by introducing the American Community Survey (ACS). A major household survey intended to include 250,000 housing units each month, the ACS would replace the decennial census long-form sample and permit continuous measurement of the same data items currently collected only every 10 years on the census long form. The 2010 census would therefore include only the short form, which would enable easier (and potentially more accurate) data collection in the census and save costs on data capture from completed paper questionnaires. At the same time, the data on characteristics currently collected on the census long form would be produced on a more timely basis, offering annual assessments rather than a static once-a-decade snapshot.

The potential rewards of the ACS are great, but so too are its inherent risks. The survey’s success is contingent on sustained long-term funding, and year-to-year fluctuations in allocated spending levels could cause severe data quality problems, particularly for small population groups. Estimation based on continuous measurement such as the ACS—most likely making use of moving averages of several years of data—also raises conceptual and feasibility issues that must be addressed in order for the survey to win support. These risks, and others, are significant, but perhaps the most important risk associated with the ACS is simply one of timing. A final decision on the methodology for the 2000 census was reached dangerously close to Census Day; extended delay in reaching agreement at all levels—the Census Bureau, the administration, and Congress—about the role of the ACS could similarly raise the risk of having to revamp census design very late in the cycle. The decision on whether the ACS will proceed in full—and, with it, determination of the fate of the census long form—is the single most important element in terms of defining the general shape, structure, and design of the 2010 census.

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