Another group of people excluded from the A.C.E. processing were residents of housing units that were temporarily removed from the census data processing in summer 2000 as part of the ad hoc operation to reduce duplication from the MAF. This operation identified 6 million people as potential duplicates whose records were temporarily deleted from the census. After further examination, 3.6 million of them were confirmed deletions, and 2.4 million were reinstated, but too late for inclusion in the A.C.E. These 2.4 million reinstated people contributed to reducing the net undercount when the dual-systems estimate from the A.C.E. was compared with the census count. They were about equally likely to be found among historically better-counted groups as among historically worse-counted groups, so they did not affect differences in net undercount rates.
The Census Bureau’s initial population estimates obtained through demographic analysis—a technique that uses birth, death, and Medicare records and estimates of net immigration to build an estimate of the population—were lower than the estimates from the census and the A.C.E. This result suggests that both the census and the A.C.E. overcounted the population. The panel finds, however, that there are serious questions about the demographic analysis, especially with regard to the methods for estimating the components of net immigration. The panel concludes that because of the uncertainties about the accuracy of the estimates of immigrants (especially the undocumented alien component) and emigrants, compounded by the difficulties of classifying people by race, demographic analysis should not be used as a standard for evaluation at this time.
Looking to the Census Bureau’s program for further evaluation of the census, the A.C.E., and demographic analysis, we urge the Bureau to devote resources to completing planned studies on as fast a schedule as practicable. The information from the 2000 evaluations is needed not only to assess the 2000 census, but also to plan for 2010.
Important aspects of census operations that we have identified for timely evaluation (some of which will be addressed in the evaluations to be released in mid-October) include:
the completeness of coverage of the group quarters population and the effects of address list development and enumeration procedures on coverage of this population;