The population figures are based on the Census Bureau’s population estimates program. Estimates of each county’s population by single year of age, race and Hispanic origin are available for July 1 of each year. The most recent year available is 2018. On or about 2000, the Census Bureau altered the racial classification to include populations of two or more races. Estimates that bridge the old and new racial categories are available at the Surveillance, Epidemiology, and End Results program (SEER) of the National Cancer Institute and were utilized in this analysis.

Other information on a county’s population, households, and home values is based on the 2000 decennial census SF3 files and the 2014-2018 American Community Survey five-year file. The 2000 census data was available on the Census Bureau’s American Factfinder site, now decommissioned, and the 2014-2018 American Community Survey tabulations are available at

Counties are classified into urban core and large suburban counties on the basis of the commonly used 2013 National Center for Health Statistics Urban-Rural Classification Scheme. The 68 urban core (or large central metro) counties are those in metros of 1 million or more population that: “1) Contain the entire population of the largest principal city of the metropolitan statistical area (MSA), or 2) Have their entire population contained in the largest principal city of the MSA, or 3) Contain at least 250,000 inhabitants of any principal city of the MSA.”3 The 370 large suburban (or large fringe metro) counties are the other counties in metros of 1 million or more population that are not urban core counties.

There are three large metros that have no suburban counties: Las Vegas-Henderson-Paradise, NV, Los Angeles-Long Beach-Anaheim, CA, and San Diego-Carlsbad, CA.

The National Center for Health Statistics documentation indicates that there are 368 large suburban counties. We analyzed 370 counties to maintain geographic consistency over time. Broomfield county in Colorado is a large suburban county in the Denver-Aurora-Lakewood, CO metro. It was created in 2001 from parts of four other counties: Adams, Boulder, Jefferson and Weld. Adams and Jefferson are large suburban counties, but not Boulder and Weld. Boulder and Weld account for the two extra counties.

The statistics presented in the report are derived by summing over all the counties. This procedure puts more emphasis on counties with larger populations, rather than, for example, giving each county equal weight. We also generated tabulations for outcomes for the median county. On most measures, trends for the median county were similar to those reported.

Dollar values are adjusted for inflation with the Consumer Price Index Research Series (CPI-U-RS) of the Bureau of Labor Statistics (BLS). This is the price index series used by the U.S. Census Bureau to deflate the data it publishes on household income and earnings. All dollar values have been rounded to the nearest thousand.