The story maps team released a Story Map Cascade that shows the simple ratio of Median Home Value to Median Income, per US County. Mortgage Magnitude helps illustrate the relative affordability of middle-class home ownership across the country.
If you read the story, and are interested in how the maps were made, you can check out the cartographic process here. If you'd like to see animated, and small-multiple, versions of these maps, you can find them here.
The data was provided by Esri Demographics.
Happy Mapping! John