To measure the U.S. unemployment rate, the Census Bureau periodically selects 60,000 households, chosen to represent different age, racial and income groups reflecting the population.
A participating household is surveyed for four consecutive months, dropped for eight, then returned for a final four months.
Selected households are notified by mail. Initial interviews are done in person and later ones by phone. They last 10 minutes.
Questions involve age, sex, race, occupation, industry of employment, number of hours worked and whether unemployed workers quit or were fired.