Demographic analysis uses records of births, deaths, and net immigration to produce updated population estimates for age and sex groups for blacks and for all others. The original 2000 demographic analysis estimates were subsequently revised in October 2001. There are sufficient uncertainties in the revised net immigration estimates (particularly the illegal component) and a revised assumption of completeness of birth registration after 1984, compounded by the difficulties of classifying people by race, so that the revised demographic analysis estimates cannot serve as the definitive standard of evaluation for the 2000 census or the A.C.E. However, the estimates were useful in helping to identify coverage problems in the census and the A.C.E., and the method is important as the basis for postcensal population estimates.
A large postenumeration survey is an essential part of a coverage measurement program for the U.S. census. Demographic analysis, which is limited to producing net national-level coverage estimates for blacks and all others by age and sex, cannot substitute for a postenumeration survey. Underscoring the need for a large survey in 2010 is the prospect that the Census Bureau will make extensive use of methods developed from 2000 A.C.E. research on matching census records by name and birthdate to reduce duplicate enumerations in the 2010 census. If that is done and if in 2010 the number of omissions were to be as large as or larger than in 2000, the consequence could be a substantial net undercount of the population and an increase in differential undercoverage among population groups. In those circumstances, it would be essential to have an improved coverage evaluation survey built on the experience of the 2000 A.C.E. to understand the coverage achieved in 2010 and to inform the public about it. Data from an improved survey would be available to develop reasonably reliable estimates of coverage errors, which would be needed not only to explain the accuracy of the census but also to permit adjustment of some or all of the data should that be considered necessary.
We therefore recommend that the Census Bureau and the administration should request, and Congress should provide, funding for