on the long-form questionnaire (see Chapter 7). Rates of missing data were even higher for residents of group quarters (e.g., college students residing in dormitories, prisoners, nursing home residents, and others).
Finding 1.4: The 2000 census experienced four major problems of enumeration: (1) errors in the Master Address File; (2) large numbers of duplicate and other erroneous enumerations in the census; (3) high rates of missing data for many long-form items; and (4) inaccuracies in enumerating residents of group quarters.
A decision by the U.S. Supreme Court in 1999 prohibited the use of sampling-based methods for generating census counts used to reapportion the U.S. House of Representatives. But the Census Bureau faced three major decision points as to whether it would use the results of the A.C.E. Program to statistically adjust 2000 census data to reflect estimated coverage errors. In March 2001 the Census Bureau weighed whether to adjust census data to be used for legislative redistricting; in October 2001 the question was whether to adjust census data for such uses as allocating federal funds to states and localities; and in March 2003 the issue was whether to use a revised set of adjusted totals as the base for postcensal population estimates. Each of these decisions was preceded by a wave of intensive evaluation studies dissecting the A.C.E. Program in great detail; at each of these decision points, the Census Bureau ultimately elected not to adjust the census data.
Finding 1.5: In March 2001, October 2001, and March 2003, the Census Bureau announced that it would not adjust the 2000 census results for incomplete coverage of some population groups (and overcounting of other groups). In our judgment, all three of the Bureau’s decisions are justified, for different reasons. The March and October 2001 decisions are justified given (1) the Bureau’s conclusion in March that evaluation studies were not sufficient to determine the quality of the A.C.E. population estimates and (2) its conclusion in October, after