On December 6, 2012, the U.S. Census Bureau released five-year American Community Survey (ACS) estimates for the combined years of 2007 through 2011, making available social, economic, housing and demographic statistics for every community in Nebraska and the nation. Also available are estimates for Nebraska’s counties.
The data are based on a rolling national sample survey mailed to about 2 million addresses each year, resulting in nearly 2 million final interviews each year from 2007 through 2011. By pooling several years of survey responses, the ACS can generate detailed statistical portraits of smaller geographies such as counties. The Census Bureau issues new sets of these five-year estimates every year, permitting users to track trends in even the smallest of areas over time. This is the third set of five-year estimates. Data for the 2005-2009 period were released in December 2010, and data for the 2006-2010 period were released in December 2011.
The new 2007-2011 ACS estimates are not related to the 2010 Census population counts that have been released. The ACS complements the decennial count and provides estimates of population characteristics that are far more detailed than the basic demographic information that has been released from the 2010 Census.
The main function of the decennial census is to provide counts of people for the purposes of congressional apportionment and legislative redistricting. As a complete count of the population, the 2010 Census data are critical for knowing how many people live in the United States, where they live and their basic demographic information such as race, sex and Hispanic origin. The ACS estimates, on the other hand, are based on a sample survey of the nation and are intended to describe the social and economic characteristics of the U.S. population, not to provide population counts.
As a result, the ACS does not provide official counts of the population in between censuses. Instead, the Census Bureau’s Population Estimates Program will continue to be the official source for annual population totals, by age, race, Hispanic origin, and sex.
For areas with populations of 65,000 or more (including the state of Nebraska; Douglas, Lancaster, and Sarpy Counties; and the cities of Lincoln and Omaha) the Census Bureau has produced 1-year ACS estimates every year since 2005. These areas require only one year of survey responses to produce reliable estimates.
Because it is a survey based on a sample of the population rather than the entire population, the ACS produces estimates, not actual counts. Since it is based on a sample, the ACS also is subject to sampling error. To aid data users, the Census Bureau calculates and publishes a margin of error for every ACS estimates it produces. These margins of error are not included in the following tables. 1
(CPAR), Center for Public Affairs Research, "Selected Characteristics for Nebraska Counties from the 2007-2011 American Community Survey" (2012). Publications since 2000. 460.