Public Use Microdata Sample (PUMS) Files from the 20th Census of Population and Housing

The "E" Sample file was constructed by the agency for researchers at the Center for Demography and Ecology at the University of Wisconsin-Madison. The "F" Sample file was constructed by the agency for researchers at the University of Pennsylvania, with some assistan ce from the National Opinion Research Center.

This series contains records for a sample (drawn from long-form questionnaires) of housing units with information on the characteristics of each unit and the people in it. Each PUMS file is a stratified random sample of the population, actually a subsample of the full census sample (19.4 percent of all households) that received census long-form questionnaires. There are three independently drawn samples, designated "A," "B," and "C," each featuring a different geographic scheme.