Map Illustrates Population Shifts behind Reapportionment Results

Detailed Population Data Reveals the Extent and Location of Change since the 2000 Census

December 23, 2010

Redlands, California—To bring context to the 2010 state population numbers the U.S. Census Bureau released Tuesday, Esri developed a map that illustrates official changes in congressional representation along with Esri’s projected county-level population change since the 2000 Census. The map depicts shifts within each state that drove the reassignment of 12 of the nation’s 435 congressional seats, impacting 18 states. Though the Census Bureau will not release its 2010 block-level population numbers until March 2011, Esri’s 2010 projected population data led to reapportionment predictions that match the Census Bureau’s results.

Esri population projections incorporate Census Bureau population estimates with data from the Internal Revenue Service, building permits, housing information, residential postal delivery counts, and other sources. A full white paper on Esri’s data projection methodology can be found at http://www.esri.com/library/whitepapers/pdfs/demographic-update-methodology-2010.pdf.

# # #

For more information on Esri data and GIS technology, e-mail Emily Meyertholen at emeyertholen@esri.com or call 909-793-2853, extension 1695.