These 3,139 county-level series come from the Dartmouth Atlas of Healthcare. The Dartmouth Atlas of Healthcare calculates the preventable hospital admissions rate by dividing the number of discharges of ambulatory care sensitive conditions per 1,000 medicare enrollees.

These 3,143 county-level series come from the U.S. Census Bureau’s American Community Survey. Each series represents the percentage of the population in a county who live below the federal poverty line.

These 3,143 series on commute time are calculated from the U.S. Census Bureau’s American Community Survey. Each series is calculated by dividing the aggregate travel time to work for all workers by the total number of workers, 16-years of age and older, who commute.

These 3,140 series are calculated from the U.S. Census Bureau’s American Community Survey. For each series, the 20:20 ratio is used to determine the level of inequality in a county. The 20:20 ratio is the ratio of the mean income for the highest quintile (top 20 percent) of earners divided by the mean income of the lowest quintile (bottom 20 percent) of earners for a particular geographical area.

These 3,143 county-level series come from the U.S. Census Bureau’s American Community Survey. A household is considered burdened if 30 percent of a household’s income is spent on rent or mortgage expenses.

FRED has added 16 monthly series on gold owned by the federal government as published by the U.S. Department of the Treasury. The Status Report of U.S. Government Gold Reserve summarizes holdings of gold by various facilities; gold coins and bullion on display at Federal Reserve Banks and in the vault at the Federal Reserve Bank of New York; and gold held by U.S. Mint facilities.

These 3,143 county-level series come from the U.S. Census Bureau’s American Community Survey. These data represent single-parent households with their own children who are younger than 18 years of age as a percentage of total households with children younger than 18 years of age.

The FRED monthly database for macroeconomic research (FRED-MD) now includes the February 2017 vintage. This database, designed for the empirical analysis of “big data,” is described in detail in a St. Louis Fed working paper by Michael W. McCracken and Serena Ng.

The FBI collects these 2,902 county-level series through their Uniform Crime Reporting Program. The data are presented as the combined violent and property crime offenses as reported by county law enforcement agencies.