tion coverage and quality of the basic demographic items before they are released.

ASSESSMENT OF BASIC AND LONG-FORM-SAMPLE DATA

Finding 7.1: Rates of missing data in 2000 were low at the national level for the basic demographic items asked of everyone (complete-count items)—age, sex, race, ethnicity, household relationship, and housing tenure. Missing data rates for these items ranged from 2 to 5 percent (including records for people with one or more missing items and people who were wholly imputed). Rates of inconsistent reporting for the basic items (as measured by comparing responses for census enumerations and matching households in the independent Accuracy and Coverage Evaluation survey) were also low. However, some population groups and geographic areas exhibited high rates of missing data and inconsistent reporting for one or more of the basic items. No assessments have yet been made of reporting errors for such items as age, nor of the effects of imputation on the distributions of basic characteristics or the relationships among them.

Finding 7.2: For the household population, missing data rates were at least moderately high (10 percent or more) for over one-half of the 2000 census long-form-sample items and very high (20 percent or more) for one-sixth of the long-form-sample items. Missing data rates also varied widely among population groups and geographic areas. By comparison with 1990, missing data rates were higher in 2000 for most long-form-sample items asked in both years and substantially higher—by 5 or more percentage points—for one-half of the items asked in both years. In addition, close to 10 percent of long-form-sample households in 2000 (similar to 1990) provided too little information for inclusion in the sample data file. When dropped households and individually missing data are considered together, the effective sample size that is available for analysis for some characteristics is 60 percent or less of the original long-form-sample size.

Many long-form-sample items had moderate to high rates of inconsistent reporting, as measured in a content reinterview sur-



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