To conduct its analysis, the Center for Public Integrity combined these data sets:
- The Federal Communication Commission’s Form 477 Broadband Deployment Data, as of June 30, 2015, the latest available;
- 2010 U.S. Census population data at the census block level, which is the most recent publicly available;
- 2010-2014 5-year American Community Survey income and demographic data at the census block group level;
- U.S. Agriculture Department rural-urban continuum codes at the county level.
The Center used the FCC’s definition of broadband, a download speed of 25 megabits per second and higher, to determine if broadband was offered by consumer providers in each census block group.
Income for Census block groups were divided into quintiles based on median household income and the number of households in each census block group. The five census block group quintiles are:
1) Below $34,783
2) From $34,783 to $46,875
3) From $46,876 to $60,223
4) From $60,224 to $80,694
5) Greater than $80,694
The Center’s analysis represents 99.5 percent of the population as measured by the Census Bureau in 2010. It includes 96.9 percent of all census blocks from 2010 and 99.1 percent of census block groups in the 2014 5-year American Community Survey. The Center did not include census block groups with no reported median income.