Strong links that hold up: 46 pairs
The link is strong (r of 0.7 or more) even comparing counties alike in density, income and education. The two move together closely. Knowing one tells you most of what the other will be, and the pattern is steady enough to follow.
Each figure is r: how closely two measures rise and fall together across counties, from −1 (one goes up as the other goes down) to +1 (they rise together). 0 means no link. “After” compares counties alike in population density, household income and the share with a degree. Open a pair for its map, the counties furthest from the trend and the checks behind it.