in better coverage and a decreased differential undercount of minorities, it would be possible to argue the merits of costs versus coverage. However, as demonstrated in Chapter 2, both the overall percentage undercount and the differential undercount (the difference of the undercount between the black and nonblack populations) apparently worsened in the 1990 census (Robinson et al., 1993). It is of course possible that the net undercount and differential undercount might have been even worse in 1990 if less had been spent on the census. Some may claim that even greater funding was needed in 1990 to decrease the undercount. However, we cannot assess these hypothetical claims in the absence of evidence. The observable evidence is that substantially more was spent on the 1990 census, and the undercount did not improve. The fact that spending more money did not produce a more accurate census was, in large part, at the center of the criticisms levied at the 1990 decennial census.4
Costs have been affected by increased legal demands for accurate small-area data (see Appendix C for extended discussion of legal requirements for census data). The ''one-person, one-vote" rulings of the Supreme Court in the 1960s and the Voting Rights Act of 1965 as extended and amended in the past 30 years have substantially expanded the requirement for accurate population data, cross-classified by age and ethnicity at the small-area level, for legislative redistricting and related purposes. And although the statutes do not specify the geographic level of detail that is required, the census now provides it at the level of individual census blocks in order to provide flexible building blocks for subsequent reaggregation by census data users. Also, over the past three decades, the number of congressional statutes calling for the use of demographic and related data to apportion federal funds among states and localities has mushroomed. Although the statutes often do not specify the use of data based on the decennial census, in practice the use of census data for these purposes is ubiquitous in the absence of alternative sources.
During this 30-year period there has also been a virtual explosion among state and local governments and private business firms in the development of computer data banks and computer models based on the use of census data at the block level for purposes of planning and operations. This has generated another set of demands for accurate small-area data. It has also raised important questions about relationships among federal, state, and local governments and private business firms with respect to the appropriate development and use of large-scale geocoding and geographic data systems (discussed in Chapter 8).
These developments, the ways that the Census Bureau has responded to them, and the ways in which they are perceived by the public have interacted with each other both to raise the costs of taking the census and to generate increased perceptions of inequity in the resultant census statistics. Thus, for example, the depressed response rate is typically lowest precisely in areas with high concentrations of minority groups, leading to substantially increased costs in an effort to minimize differential undercount and produce accurate data. Despite