The American Community Survey (ACS) is an national survey by the U.S. Census Bureau that has replaced the “long form” portion of the decennial census. It’s important to note that the ACS is an estimate — that is, the data are based on a sample of the whole population. It is not an enumeration, where everyone is counted (as in the decennial census “short forms”).
The MCDC ACS profiles include the most-used data items from the U.S. Census Bureau’s American Community Survey summary data products. The profile reports also include additional data points derived from ACS sources.
This application allows you to select and compare up to four geographic areas (of the same or mixed levels) over a single time period. In addition to the web-based profile report output, reports are also available in Excel or PDF formats.
- One-year data: 2006–2014; only areas larger than 65,000 population
- Three-year data: 2005–2013; only areas larger than 20,000 population (excluding ZIP codes and state legislative districts)
- Five-year data: 2005–2014; all U.S. areas at block group level or larger
The MCDC ACS trend reports contain the same data and features as the ACS profiles. The trend reports compare data from a single geographic area over two or more ACS reporting periods of comparable duration (i.e., one-, three-, or five-year data). Select only two periods to see the percentage change between those periods. Data availability is the same as for the ACS Profiles.
These two self-paced tutorials explain and demonstrate basic use of the ACS Profiles and ACS Trends applications.
The ACS survey is mailed to about 250,000 households nationwide every month of every year. In any given year, about 2.5% (one in 40) of U.S. households will receive the survey. Over any five-year period, about one in eight households should be sampled (compared to about one in six that received the census long form in the 2000 census). The Bureau’s strategy of sampling for non-response results in something closer to one in 11 households actually participating in the survey over any five-year period.
ACS data are reported at summary levels ranging from the entire nation down to the block group level. (Block-level data is not included in the ACS.)
There are three ACS data releases every year, with different geographic coverage for each:
- For areas with populations of 65,000 or more (the nation, states, counties, many cities, and other large areas), the single most recent year of survey data will be published annually as one-year data (e.g., 2012).
- For areas with populations of 20,000 or more, the three most recent consecutive years of survey data will be published annually as three-year data (e.g., 2010–2012).
- For areas with populations under 20,000, the five most recent consecutive years of survey data will be published annually as five-year data (e.g., 2008-2012). One exception: Data at the ZIP code and state legislative district levels is published only as five-year estimates, even though there are many ZIP codes and legislative districts that meet the 20,000 threshold.
Note that the three (or five) -year data releases do not represent a simple addition or “moving average” of multiple years of data. Data of different period lengths cannot be meaningfully compared.
For more information