The census and March CPS employ significantly different approaches to data collection. The resulting census data are, therefore, more subject to errors concerning income definitions and errors of omission. Poverty universe differences. The census and the March CPS differ in their definitions of the universe for computing poverty. Both the CPS and the census exclude the institutionalized population and foster children under age 15 from the poverty universe.
Unrelated subfamilies are family groups unrelated to the householder.
Unrelated subfamily members under age 15. The census poverty universe definition excludes members of unrelated subfamilies under age 15. The CPS includes them in the poverty universe. Excluding of these unrelated subfamily members from the census poverty universe removed a relatively large group of poor persons from the total poverty count. While one cannot compute the number of poor excluded from the census itself, one can use the CPS as a proxy.