areas. When that production begins, however, the Census Bureau will be in the position of having two related flagship products—the decennial census and the ACS—follow two very discrepant residence models. How this discrepancy will affect estimates of population characteristics, and the extent of the gap that may arise between ACS and census estimates in decennial census years, is unknown. However, the coexistence of the census and the ACS makes the choice of residence standard as an open and important issue; we discuss the ACS and the census residence standards in detail in Chapter 8.
Both the de jure and de facto ideals have strengths and weaknesses. One is not clearly superior to the other; rather, the choice between which standard to follow depends critically on the uses of the resulting data. The case can be made that a pure de facto count is the least ambiguous concept for respondents to understand, and it may be the simplest to describe: “Who is here right now?” As a result, “current residence” models based on a de facto approach are generally considered easier to explain and implement; they have become the standard for many surveys and polls, as their point-in-time snapshot orientation makes them well suited for measuring the characteristics of a population (rather than an absolute count). However, for purposes of reallocating political representation based on population counts, the emphasis in a pure de facto model on counting people exactly where they are found would emphasize people’s stays in situations that are temporary or transitory: away on trips, in hotels or motels or staying as houseguests, or in transit at the time of the count. As a result, a de facto approach would arguably be less appropriate than a de jure-type rule that counts people where they belong, in some legal or other sense.
Some nations strive for the de jure ideal by maintaining population registers or using counts derived from administrative records in lieu of a census. Appendix B summarizes residence concepts used in several foreign nations that—like the United States—conduct regular population censuses rather than compile records-based counts. Of these countries, most adhere to a de jure-type concept: Austria, Canada, Finland, Israel, Italy, Portugal, Switzerland, and the United Kingdom (the United Kingdom switched to a de jure count in 2001 after using a de facto standard since 1801). However, that choice is not universal. Australia, Estonia, Ireland, New Zealand, and South Africa use a strict de facto standard; Japan uses a 3-month hybrid rule akin to the ACS rule. Several nations, among them Japan and New Zealand, ask both usual residence and current residence questions; perhaps more interesting are cases like Austria and Finland, which ask their respondents to identify their “main” or “permanent” residence but also ask them for a “secondary” or “temporary” residence if one exists. Likewise, de facto-type rules are common in general surveys and polls, but some major federal household surveys vary and follow a usual residence rule: prominent among these are the Census Bureauconducted Current Population Survey and the Survey of Income and Program