This report is the first installment in the panel’s work. Some of the topics taken up in this interim report will be examined in more depth in the panel’s final report.

Broadly speaking, coverage measurement potentially serves three primary uses: (1) assessment of coverage accuracy, (2) guidance for improvement of census processes, and (3) adjustment of reported counts.

Census counts are used for many purposes vital to the nation, including the apportionment of seats in the U.S. House of Representatives (the constitutional mandate of the census); federal, state, and local redistricting; fund allocation to state and local jurisdictions; public planning; and learning about the population. Consequently, it is important for the nation to monitor the quality of population coverage overall and that of demographic or other groups. The purpose of the Census Bureau’s coverage measurement programs for the 1950, 1960, and 1970 censuses was primarily to inform users as to the quality of census coverage.

In addition to providing information to users about census quality, coverage measurement programs were also used to identify components of census processes that, if improved, could potentially reduce net coverage problems in the next census. For example, the relatively high undercoverage rate of black men ages 20 to 54 in the 1970 census motivated the implementation of several coverage improvement programs in the 1980 census. One such program, the nonhousehold sources program, which looked for names on certain administrative lists that did not match to census records, aimed to reduce differential coverage—that is, the difference between net coverage for a specific demographic group compared with that for the nation as a whole. However, the information that these coverage measurement programs provided was not very specific for identifying which components of the census process needed modification to address the measured undercoverage.

Starting with the 1980 census, an additional use was proposed for coverage evaluation programs, which was to use the information to adjust the census for