Map #94: July 9, 2018

Difficulty Level: 8

Click here for a full-size version of this week’s map.

This map is a choropleth of the counties of the United States. (Do you need a refresher on what a choropleth is? Visit our “Basics” page for a quick primer.) This map was submitted by Carl, a rising twelfth-grader who is a regular submitter on this site. It’s a fairly tricky map, so be careful! As always, your job is to figure out what this choropleth represents.

Ready to submit your solution? Click here to be taken to the submission page.

Stumped? Check back Wednesday, next Monday, next Wednesday, and next Friday for hints about where to focus your investigation. The answer will be posted on Monday, July 23, 2018. Good luck!

Wednesday’s hint: The first thing to notice is that there’s an unusual pattern in urban areas. In some cases, large cities stand out on this map, but in most cases, it’s actually the suburbs of large cities that appear darker. You can see this pattern in Miami, San Francisco, Portland, Chicago, Detroit, Boston, and Washington.

Monday’s hint: One important note about this map is that the scale exaggerates some pretty small numbers. A county need only have around 5% density of the statistic in question in order to get a fairly dark color. With that in mind, let’s take a look at Florida’s Palm Beach County, up the coast from Miami. It’s a fairly suburban county in the wider orbit of the Miami metropolitan area, and it is home to a lot of people who have moved there from elsewhere on the East Coast. What else do you know about the sort of person who might live in Palm Beach County?