cial purposes in 1990, there was no statistically satisfactory way of assigning household characteristics to the added persons. Files for people included through adjustment would have been added to the census data files by imputing individuals from the appropriate poststrata. These individuals' housing types would have been listed as special quarters, that is, they would not have been placed in distinct households.

For the 2000 census the Census Bureau initiated a research project early in the 1990s to determine if something more effective could be done. Specifically, the Bureau examined the creation of a so-called transparent file in which all of the additions obtained through use of integrated coverage measurement would be incorporated into the distribution of households and thus be transparent to data users.12 The Bureau's initial plan would have altered the relative weighting of larger versus smaller households in order to obtain the desired counts of persons by demographic characteristics. Thus for example, three-person households with certain characteristics might be increased while two-person households with otherwise similar characteristics were reduced.

The initial procedure presented by the Census Bureau raised a concern for the panel. The panel's views were informed by other research in this general area (see Zaslavsky, 1988; Zanutto and Zaslavsky, 1996). However, no other approach had been demonstrated to be feasible in a large-scale production setting. It is our understanding that recent advances to the initial procedure may have addressed the panel's concern. But because the Census Bureau's decision on whether to integrate this into the production operation had to be made on the basis of the performance of the initial procedure, the panel understands the decision to essentially repeat the method of the 1990 census, i.e., persons added through use of integrated coverage measurement will be assigned for their household, to the special quarters category. Especially given the limited time for evaluation of statistical models, this seems to be a reasonable decision for 2000. However, the panel strongly supports the Bureau's intention to produce the transparent file at a later date.


The transparent file and other data products based on it would have no flags or indicators of which household records resulted from imputations and which household records were directly collected from respondents. This makes sense since the fact that some households are replicated and some dropped using this methodology makes the notion of an imputation not clearly applicable.

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement