The American Community Survey (ACS) helps local officials, community leaders, and businesses understand the changes taking place in their communities. It is the premier source for detailed population and housing information about our nation.
The American Community Survey is a demographics survey program conducted by the U.S. Census Bureau.It regularly gathers information previously contained only in the long form of the decennial census, such as ancestry, citizenship, educational attainment, income, language proficiency, migration, disability, employment, and housing characteristics. These data are used by many public-sector, private-sector, and not-for-profit stakeholders to allocate funding, track shifting demographics, plan for emergencies, and learn about local communities. Sent to approximately 295,000 addresses monthly, it is the largest household survey that the Census Bureau administers. The American Community Survey gathers information annually in the 50U.S. states, the District of Columbia, and Puerto Rico — it does not gather information in four major U.S.territories.
Learn more at: https://www.census.gov/programs-surveys/acs/
1-year data reflects estimates for a given calendar year. For example, 2018 ACS estimates cover the period from January to December, 2018.The main advantages of 1-year ACS data estimates:
They reflect the most current data available.
They provide estimates for specific years, which is especially useful for any significant local or national changes that could affect those estimates (e.g., the Great Recession 2007-2009).
The 5-year data reflects estimates for a period of 5calendar years. For example, the 2014-2018 ACS estimates cover the period from January 2014 toDecember 2018.
The main advantage of using 5-year estimates is that the samples are larger; therefore, they increase the statistical reliability of the estimates produced, especially when looking at subgroups in the data.
5-year estimates are calculations (more or less averages) that are designed to show cumulative (or overall) changes over a 5-year period. If the unemployment rate is 10% from 2007-2011, then that could result from:
a constant percentage of 10% across those 5 years (i.e., 10% unemployment in 2007, 2008, 2009, 2010, and 2011);
a steady increase from, say, 7% to 13% or a corresponding decrease; or
any other increase and decrease across all the years.
Comparing 5-year estimates to 1-year estimates can help contextualize the patterns in the 5-year data to better understand if the estimate was relatively constant or if it fluctuated over time.