Data on population aging and older population of the United States and the world are available from a variety of Census Bureau sources. Listed below are the surveys, censuses, and programs that contribute data and other content to U.S. older population.
The American Community Survey (ACS) is an annual, nationwide survey of more than 3.5 million households in the U.S. The ACS is part of the Decennial Census Program and replaces the long form, which the Census Bureau last used during Census 2000. The survey produces statistics on demographic, social, economic, and other characteristics about our nation's population and housing. We release ACS 1-year estimates in September for the pervious calendar year and 5-year estimates in December for the previous five calendar years.
The Current Population Survey (CPS) is the primary source of labor force statistics for the population of the U.S. The Bureau of Labor Statistics sponsors the survey, and the U.S. Census Bureau conducts the data each month. The CPS involves a sample of about 60,000 occupied households. Households are in the survey for four consecutive months, out for eight, and then return for another four months before leaving the sample permanently.
The decennial census counts every resident in the U.S. once every ten years, in years ending in zero. The Constitution of the United States mandates the head count to make sure each state can fairly represent its population in the U.S. House of Representatives. States use the numbers to draw their legislative districts. The federal government uses them to distribute funds and assistance to states and localities.
The Census Bureau's Population Estimates Program (PEP) produces estimates of the population for the United States, its states, counties, cities, and towns, as well as for the Commonwealth of Puerto Rico and its municipios. Demographic components of population change (births, deaths, and migration) are produced at the national, state, and county levels of geography. Additionally, housing unit estimates are produced for the nation, states, and counties.
PEP annually utilizes current data on births, deaths, and migration to calculate population change since the most recent decennial census and produce a time series of estimates of population, demographic components of change, and housing units. The annual time series of estimates begins with the most recent decennial census data and extends to the vintage year.
Population projections are estimates of the population for future dates. They are typically based on an estimated population consistent with the most recent decennial census and are produced using the cohort-component method. Projections illustrate possible courses of population change based on assumptions about future births, deaths, net international migration, and domestic migration. In some cases, several series of projections are produced based on alternative assumptions for future fertility, life expectancy, net international migration, and (for state-level projections) state-to-state or domestic migration.