The American Community Survey

The American Community Survey (ACS) is a nationwide survey conducted by the US Census Bureau that is administered on a rolling basis to determine federal and state fund allocations amounting to over $400 billion per year.

Prior to the creation of the ACS, up-to-date nationwide data was much harder to acquire, as the data from the decennial census would become outdated by the time a new census was conducted.  In order to provide a more current demographic summary of our populace, the US Census Bureau began developing and testing the sample survey now known as the ACS.  Launched nationally in January 2005, the ACS now allows for a much more current overview of our nation's demography.

The ACS is conducted on a rolling basis, sampling roughly 250,000 housing each month.  Through this format, single-year estimates are released for areas that have at least 65,000 residents, while three-year releases makes estimates for all places with at least 20,000 residents (areas with smaller populations have samples too small to provide accurate estimates).  Five-year ACS releases collect a sufficient amount of data to provide information at the census tract and block levels, similar to the decennial census long form.  Occasionally, samples for specific geographies still have prohibitively high sampling errors; such geographies will be "suppressed", and data will not be released.  In general, however, the ACS has provided accurate annual estimates which allows demographers (and CensusScope) to track demographic changes more thoroughly.

Although CensusScope still utilizes the US Decennial Census in many cases (historical data before the ACS was created as well as the 2010 Census), CensusScope utilizes American Community Survey data for trend information since 2005 as well as for data that have not yet been released from the 2010 Census.