As it turned out, the Bureau concluded that the evaluation studies did not provide sufficient information to decide that adjusted counts would be clearly preferable to unadjusted counts for redistricting. Although not mentioned by the Census Bureau, reaching a conclusion on this point is more difficult when the adjustments to be made for population groups are generally small11

The panel does not necessarily agree with the weight that the Bureau gave to each factor in its decision: specifically, we conclude that demographic analysis estimates are sufficiently uncertain that they should not be used as a standard for evaluation at this time (see Chapter 5). Nonetheless, we believe that the Bureau followed a reasonable process. We also believe that its decision not to recommend adjusting the census data in March was justifiable, given its conclusion that additional evaluations of the quality of the A.C.E. —and of the census itself—were needed to resolve its concerns.

The fact that the Bureau did not recommend adjusting the census counts to be provided for redistricting does not carry any implications for the usefulness of statistical adjustment methods based on dual-systems estimation. In particular, the panel views it as an open question whether adjusted counts would constitute an improvement over unadjusted counts for such purposes as fund allocation. The panel will assess the Census Bureau’s October decision on the basis of the evidence available at that time (see Part I).


This interim report provides a preliminary assessment of census and A.C.E. operations, briefly reviews the Bureau’s demographic analysis, and examines the puzzle from the reduction in net undercount measured by the A.C.E. The report does not address the superiority of one or the other set of population counts (the census or the A.C.E. estimates) for particular uses of the data.

The information available to the panel in preparing this report is extensive but does not make it possible to draw definite conclusions about the quality of the census operations or the quality of the resulting data. This report reviews the available information to identify areas for further research and to provide background for subsequent reports of the panel. The panel may revise its interim assessments when new information becomes available.

This report has eight chapters (including this introduction), a glossary, and three appendixes. Chapter 2 considers evaluation issues, including the multiple uses of census data (which complicate the task of evaluation), sources of error in the census (from which no data collection or estimation effort can be completely free), and types of evaluation. Chapter 3 provides background information on 2000 census operations, noting important differences from the


A small (or zero) net undercount for the population as a whole is not a reason for or against adjustment because net undercounts can mask sizable gross errors of omissions and erroneously included enumerations. The issue is how the balance between these components of error differs among population groups and geographic areas, resulting in different net undercount rates.

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement