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About the Data (Methodology) Main

ACS 1999-2001 and Census 2000 Comparison Study

Multiyear Estimates Study

Data Collection & Processing

Evaluation Report Series

  »  2003 ASA Documents
  »  Working Papers

2006 ACS Content Test
  » Report Series



This overview provides:

Note for users

The Multiyear Estimates Study data are being released for research purposes only. The Census Bureau has produced these data to test production methods and is releasing these data publicly for users with an interest in learning more about the characteristics of multiyear estimates. The Census Bureau will release the first official multiyear estimates for the entire country in August 2008 as 3-year estimates covering 2005 - 2007. In August 2010 the Census Bureau will release the first official set of 5-year estimates covering 2005 - 2009. By providing these research data, users are getting a valuable "advance" preview. The same disclosure avoidance procedures that are used for the standard ACS data products have been applied to these data.

It is important to recognize that the estimates included in these data profiles have not undergone the subject matter and technical review required for standard ACS data releases. For this reason these estimates are not official estimates. We strongly suggest that users consult with Census Bureau staff before drawing conclusions or taking actions based on these data.

The Census Bureau is conducting a series of evaluations using these data. If you have questions, comments, or identify any areas of concern, we would like to hear from you. Please contact us by email at


Beginning in the summer of 2006, the Census Bureau released data from the American Community Survey (ACS) for the nation and for states, counties, and other geographic areas with populations of 65,000 and greater. These data were based on a single year of data collection and are therefore 1-year estimates. In the summer of 2008 the Census Bureau will release the first set of multiyear estimates for the nation. These 3-year estimates will be based on data collected in 2005 - 2007 and will include geographic areas with populations of 20,000 and greater. In 2010, 5-year estimates will be released for the smallest of geographic areas based on data collected in 2005 - 2009.

Multiyear Estimates Study

In preparation for the 2008 release of multiyear estimates and to help data users begin to understand the characteristics of multiyear estimates, the Census Bureau conducted this Multiyear Estimates Study. Data profiles that include demographic, social, economic, and housing characteristics were produced for a broad set of geographic areas in 34 counties. Data products are available for counties, place parts, MCDs, school districts, Public Use Microdata Areas, ZipCode Tabulation Areas, American Indian areas, tracts, and block groups. Details on this study, including a full inventory of the geographic areas and products available can be found at About the Multiyear Estimates Study.

Study Universe

The 34 counties included in this study are a subset of the ACS test counties that have been used in the past for special evaluations of the ACS. They are listed below.

County State   County State
Pima County Arizona   Lake County Montana
Jefferson County Arkansas   Douglas County Nebraska
San Francisco County California   Otero County New Mexico
Tulare County California   Bronx County New York
Broward County Florida   Rockland County New York
Upson County Georgia   Franklin County Ohio
Lake County Illinois   Multnomah County Oregon
Miami County Indiana   Fulton County Pennsylvania
Black Hawk County Iowa   Schuylkill County Pennsylvania
De Soto Parish Louisiana   Sevier County Tennessee
Calvert County Maryland   Starr County Texas
Hampden County Massachusetts   Zapata County Texas
Madison County Mississippi   Petersburg City Virginia
Iron County Missouri   Yakima County Washington
Reynolds County Missouri   Ohio County West Virginia
Washington County Missouri   Oneida County Wisconsin
Flathead County Montana   Vilas County Wisconsin

Data Sets

A total of 14 data sets were created including:

  • 1-year estimates for 2000, 2001, 2002, 2003, 2004, and 2005;
  • 3-year estimates for 1999-2001, 2000-2002, 2001-2003, 2002-2004, and 2003-2005;
  • 5-year estimates for 1999-2003, 2000-2004, and 2001-2005.

How to Access Data

This web site provides access to the Multiyear Estimates Study data profiles. To begin reviewing the data, please go to Online Data. You will be prompted to select a specific data set, a test county, and then a specific geographic area. The data profile includes the period estimates and their associated margins of error. Both estimated totals and estimated percentages are displayed.

Supporting Documentation

This website also provides background and reference materials for your review. If you go to Statistical Methodology you will find a description of the methods that were used to produce these estimates and information about sampling and nonsampling errors associated with these data. A set of questions and answers about the methods, evaluations, and limitations of these data are also available at Questions & Answers.

Source: U.S. Census Bureau  |  American Community Survey Office  |  Page Last Modified: September 30, 2008