The map shows, for each U.S. county, the percentage of households that are “burdened.” That seems to be a rather vague term, but in this case it has a precise definition from the U.S. Bureau of the Census: A household is considered burdened if it has to dedicate at least 30 percent of its income to rent or mortgage payments. Clearly, there are two components that can make a household burdened: low income and high housing costs. You could probably conceive of stories for the reasons that various parts of the country are more or less burdened. (On the map, the darker the color, the more burdened the county.) Consider that major population basins have higher housing costs, the South is generally poorer, and Florida has a lot of retirees on fixed income. Of course, one shouldn’t be surprised that housing costs are higher where there are more public amenities—which is where population tends to be denser. And, of course, some households may simply choose to spend more on their homes.
But why is 30 percent used as a threshold for burden? This is the maximum that is considered by rental assistance programs as well as guidance by mortgage providers. The concern is that households should have 70 percent available for other necessities. This problem tends to apply only to poorer households, although this map covers all households.
How this map was created: Go to GeoFRED and select the county maps. Look for “Burdened Households” in the dropdown menu.
Suggested by Christian Zimmermann.