issues. The Bureau also succeeded in hiring the massive workforce required for census field operations, completed follow-up of nonresponding households in a timely manner, and made effective use of new technology for data input (see Chapter 4).
Finding 1.2: The decline in mail response rates observed in the 1980 and 1990 censuses was successfully halted in the 2000 census, and most census operations were well executed and completed on or ahead of schedule.
Finally, the Bureau made progress toward one of its major goals, which was to reduce differential net undercount rates between historically less-well-counted groups (minorities, renters, and children) and others compared with 1990 (see Chapter 6). Such reductions generally imply reductions as well in differential net undercount rates among states and other geographic areas. This assessment is based on comparing the results from the 1990 Post-Enumeration Survey (PES) and the 2000 A.C.E. Program as originally estimated. Subsequent revisions of the A.C.E. estimates are difficult to compare with the PES, but they do not contradict this assessment (see Chapter 6).
Finding 1.3: Although significant differences in methods for estimating net undercount in the 1990 Post-Enumeration Survey and the most recent revision of the 2000 Accuracy and Coverage Evaluation Program make it difficult to compare net undercount estimates, there is sufficient evidence to conclude that the 2000 census was successful in reducing the differences in national net undercount rates between historically less-well-counted groups (minorities, renters, children) and others.
Although the census was successful in achieving its overall goals for mail response, timely execution of operations, and reduction in differential net undercount, it also experienced problems. They included large numbers of duplicate enumerations—because of undetected duplications in the MAF and people being reported by two households—and high rates of missing data for many content items