Census Bureau Director Dr. Kenneth Prewitt publicly noted the importance of local accuracy in Census 2000, describing the census as an effort to find approximately 275 million residents "and make certain we know where they are living on April1st…it’s both a huge count, of course – it’s everyone – but it’s also a count that has to identify residency as of that date, because it is residency that determines allocation of congressional seats, state legislative seats and, of course, federal funds."29

Dr. Prewitt’s emphasis on local accuracy seems out of step with the Bureau’s enthusiasm to adjust census numbers by statistical sampling. History and analysis have repeatedly questioned the ability of the Bureau’s statistical adjustment techniques to provide accurate block-level data in the census. The Secretary of Commerce did so in 1990; the Supreme Court did so in 1996; 30 top Bureau officials did so in 1992 31 and again in 1998; 32 noted statisticians and demographers did so in 1998. 33 In 1997, the National Academy of Sciences reported, "With any reasonable sampling scheme that might be used nationally, there will be some levels of aggregation (for example, census blocks) for which the census count will be less precise on average and would arguably not be an improvement over what could be obtained without the use of sampling."34


Former Bureau Director Barbara Bryant summarized the problem when she reported the findings of a group of the Bureau’s high-level statisticians and demographers, writing, "Their work [CAPE committee] suggests that no survey – either the high-quality, well controlled and interviewed 1990 PES of 170,000 households or a larger one – can be used to make a post-census fine tuning of an average undercount as small as 1.6 percent in all types of places, counties and states at a level of accuracy beyond that by which surveys are usually judged."35