Census_Coverage

This project involves a study of four issues concerning census coverage estimation with the goal of developing improved methods for use in evaluating coverage of the 2010 census. A panel of experts will conduct the study under the auspices of the Committee on National Statistics of the Division of Behavioral and Social Sciences and Education. The panel is charged to review Census Bureau work on these topics and recommend directions for research. The panel’s work may require development of statistical models to extend the dual-systems estimation approach, and may also include suggestions for the use of auxiliary data sources such as administrative records.

Dual system estimation (DSE), as applied to the 1990 and 2000 censuses, had several benefits as well as limitations as a means for estimating net census coverage. Some of the limitations were:

1. The approach was designed for estimating net census coverage errors and did not provide accurate estimates of gross coverage errors, i.e., of gross census omissions separate from gross census erroneous enumerations. In the DSE approach applied in the 1990 and 2000 censuses, certain census enumerations classified as erroneous were balanced against certain coverage survey cases classified as nonmatches (census omissions) for the purpose of estimating net census coverage. Some of these paired census enumerations and coverage survey cases did not necessarily reflect gross errors.

2. The application of DSE in Accuracy and Coverage Evaluation (A.C.E.) Revision II during the 2000 census accounted for duplicates found in the census in a simplistic way due to lack of information as to which member of a duplicate pair was a correct enumeration and which was an erroneous enumeration. This led to estimation error, as did the simplistic treatment of A.C.E. cases (P-sample) that matched to census enumerations outside the search area.

3. The post-stratification approach used to apply the DSE had certain limitations. First, the number of factors that could be included in the post-stratification was limited because the approach cross-classified the factors, so that each factor added to the post-stratification greatly split the sample. (Collapsing of post-strata was needed because many of the cross-classified cells had small sample sizes.) Second, the synthetic error that arose from the synthetic application of the post-stratum coverage correction factors to produce estimates for subnational areas and population subgroups was not reflected in their corresponding variance estimates.

4. Comparisons of aggregate tabulations of DSEs with estimates from demographic analysis (DA), in both 1990 and 2000, suggested underestimation by DSE of persons missed by both the census and the coverage survey (correlation bias). In the 2000 A.C.E. Revision II, sex ratios from DA were used to determine factors to correct adult male estimates for correlation bias, assuming no correlation bias for children and adult females. This approach appeared effective for adult Blacks, but there were concerns about the appropriateness of its assumptions for other race/origin groups (particularly Hispanics). Also, DA totals for young children (0-9) exceeded the corresponding aggregated DSEs from A.C.E. Revision II by a sufficient amount to suggest possible correlation bias in estimates for young children.

The Census Bureau is interested in improving the DSE methodology to address the above issues to the extent possible, to develop improved methods for estimating coverage of the 2010 census, both in regard to net errors and gross errors.

ROBERT BELL (Chair), AT&T Laboratories
JEFFREY PASSEL, The Urban Institute
LAWRENCE BROWN, The Wharton School, University of Pennsylvania
RODERICK LITTLE, Departments of Biostatistics and Statistics, University of Michigan
XIAO-LI MENG, Department of Statistics, Harvard University
DONALD YLVISAKER, Department of Statistics, UCLA
ALAN ZASLAVSKY, Department of Health Care Policy, Harvard Medical School