New Three-Year Estimates Released for 2006-2008

The Census Bureau released the newest 3-year estimates for 2006-2008 from the American Community Survey on October 27, 2009. In September the Bureau released 1-year estimates from the 2008 ACS. If all of these releases are beginning to get confusing, here is a quick explanation.

The American Community Survey is an ongoing survey and is being released in three primary data sets; one-year estimates, three-year aggregate estimates and five-year aggregate estimates. The aggregated data over several years allows the Bureau to create estimates for geographies with smaller populations. The population thresholds are as follows:

1-year estimates are released annually for geographic areas with 65,000+ population.
3-year estimates are released annually for geographic areas with 20,000+ population.
5-year estimates will be released annually down to the Block Group level beginning in 2010. Block Groups vary in population but average around 1,500 people.

Areas with 65,000+ will have estimates from all three of these data sets, so you will need to choose which is best for your purposes for these geographic areas: a 1-year estimate with the smaller sample and greater margin of error, or a 3-year or 5-year sample that has smaller margin of error, but some of the data will be older than in the 1-year estimates.

Here is a link to some great resources for better understanding the different ACS data releases. And the Bureau has made available a series of handbooks in PDF that do a good job of addressing how different groups of people can access and understand the ACS data, with illustrated examples of how to download the data and understand what you are looking at when you do.

The biggest thing to remember is that the Decennial Census is a point-in-time sample reflecting totals on April 1 of the census year and the ACS data are obtained throughout the year, and even aggregated over a period of years. Here is a link to estimates for poverty status, income, home values for the 55 Kentucky counties that are available in this newest data release.