A critical question for the future of federal statistics is in what ways the ACS can contribute to and in what ways it can borrow strength from the other major national household surveys. At this early stage of implementation of the ACS, it would be foolish to think about dropping or curtailing another survey because its content overlaps with the ACS. Instead, what is needed is in-depth research to compare estimates, determine the strengths and weaknesses of each, and develop methods to improve both the ACS and other surveys. Each will undoubtedly continue to have an important role to play—the ACS primarily by providing small-area estimates and other household surveys primarily by supporting rich, multivariate policy analysis and basic social science research. The challenge will be to integrate the ACS and other surveys in ways that strengthen them all.
One way in which the ACS can help other household surveys involves the MAF sampling frame. Assuming that the advent of the ACS will lead to continuous updating and improvement of the MAF (see Section 4-A.4), it should be possible to update the sampling frames for other surveys more than once a decade. Indeed, the Census Bureau plans to adopt the MAF as the sampling frame for its other household surveys. In addition, responses to the ACS could be used to identify population groups of interest for oversampling in other surveys.
With regard to improved estimates for overlapping content items, the ACS could likely help other surveys—and vice versa—in several ways. For example, if research establishes that ACS estimates of a particular item are comparable with those for that item in another survey, the ACS could provide valuable controls for the other survey. But if research establishes that the ACS estimates are less accurate than those from another survey, estimates from the other survey might be used to calibrate the ACS estimates for small subgroups in some simple model-based way.
For key items of national importance, it might become possible to use the ACS, other surveys, and administrative records to develop the best estimates for the nation, states, and, possibly, substate areas. These estimates could be published as independent time series, similar to the estimates of gross domestic product, which draw on many data sources.
Recommendation 7-10: As part of its research and development program for the ACS, the Census Bureau should dedicate a portion of resources to pursue innovative, longer term projects. While short-term research and development must focus on the ACS as a replacement for the census long-form sample, research must also address how the ACS can improve the nation’s information on population and housing in ways that were not possible with the long-form sample and may not even be envisioned today.