Information on the Accuracy of Address Coverage
GGD-00-29R: Published: Nov 19, 1999. Publicly Released: Nov 19, 1999.
- Full Report:
Pursuant to a congressional request, GAO provided information on the: (1) extent to which the accuracy of the 1990 census address counts varied by geographic area; and (2) difficulties that the Bureau of the Census faces in building a quality address list.
GAO noted that: (1) Bureau evaluations of the 1990 census suggest that census housing unit coverage was less accurate in rural areas than it was urban areas; (2) specifically, the Bureau estimated gross omissions from the census of about 7 percent of the housing units in rural areas, compared to between 2 and 3 percent in urban areas; (3) the evaluations suggest that a number of factors could have contributed to the errors; (4) they include operational difficulties that temporary census workers encountered when trying to build the address list; (5) in some cases, for example, census workers had to make difficult judgments about whether buildings were "vacant and boarded up" (and thus should be included on the census address list) or "not fit for habitation" (and thus should be excluded from the list); (6) the type of structure also affected error rates; (7) for example, small multiunit dwellings sometimes contained housing units that did not appear on the mailing lists the Bureau used to develop its census address list; (8) the Bureau redesigned its address list development strategy for the 2000 census, adding operations that it believes will result in an address list at least as good as the one used in 1990; (9) nevertheless, identifying and locating the nation's estimated 119 million housing units remain a huge and complex task; (10) some difficulties were evident during the Bureau's block canvassing operation, where census workers encountered gated communities and "hidden" housing units such as basement apartments and thus had to use their judgment concerning the existence of housing units; and (11) the workers' decisions will affect whether census questionnaires will be properly delivered to those households in 2000.