meration of “other citizens” was again conducted on a voluntary basis and the results—as in previous tentative tests—showed low reporting. Mills (1993:46) suggests that “a post-1970 census comparison of data from the 1970 overseas census with country of birth/citizenship data from individual foreign censuses indicated that the census counts for private U.S. citizens represented a substantial undercount, particularly in Canada and Mexico, where the underenumeration probably exceeded 90 percent.”
The Census Bureau reversed itself in the 1980 census, electing to exclude all overseas population from the apportionment counts. The then substantially smaller deployment of military personnel overseas was the major reason for the reversal; the Census Bureau also expressed concerns on the reliability of data on a person’s “home state.” The 1980 census was also distinctive in that no attempt was made to directly enumerate any part of the overseas population; instead, administrative record counts (but no data on characteristics) for armed forces, civilian employees, and their overseas dependents were obtained from the Department of Defense and the Office of Personnel Management and tallied as a separate “overseas population” count. Citing low participation in the 1960 and 1970 efforts, no data or counts of “other citizens” not affiliated with the federal government were collected. Zitter (1987) argued that the Census Bureau’s attempt to count the overseas population in 1980 was minimal in comparison with earlier censuses; anything that distracted from the main census event was deemed an unnecessary risk and was not to be undertaken without a compelling reason, such as a congressional mandate.
For the 1990 census, overseas military and federal employees were again counted by administrative records. The overseas military population and their dependents living with them were counted by using Department of Defense records; federal employees and their dependents were similarly addressed using Office of Personnel Management records. No effort was made to count “other citizens” living abroad.
However, the Bureau reversed itself on including military and federal civilian employees in apportionment totals, returning to the 1970 policy of including them in their home states’ counts. The change owed a great deal to increased congressional interest in the issue, which grew as both the overseas Americans issue and the inclusion of undocumented immigrants emerged as major issues and potential sources of litigation (McMillen, 2000a).
In a background paper to inform the panel’s deliberations, Lowenthal (2005) summarized the congressional interest, despite the absence of large numbers of American troops abroad: