Introduction and background

The mission of decennial censuses in the United States is to count everyone living in the country once, only once, and in the right place. The counts are important for the following decade because census results are used for redistricting, allocating seats in the House of Representatives as well as providing information to distribute as much as $400 billion in federal funds annually. Fulfilling this mission is daunting in a country that is growing increasingly more diverse and complex.

The problem

Despite best efforts to count everyone, the US Census Bureau’s own research shows persistent differential undercounts of some hard-to-count minority populations, such as African-Americans and Hispanics, across decennial censuses. Post-enumeration surveys and statistical studies have given estimates of the number of persons both missed and erroneously counted by the census and their characteristics. Ethnographic studies conducted during census data collections, but separate from those operations, have identified a range of factors affecting coverage and illuminated how and why they may affect enumeration in some racial and ethnic subpopulations. Though there is no reason to believe that race or ethnicity in and of itself leads to coverage error, it seems that some underlying variables associated in past studies with undercounting may also be correlated with race (e.g., mobility, complex living situations, and language isolation). Other variables with hypothesized links to both undercoverage and race for possible future research include poverty, immigration, and legal status.