Reader Tyson A. serves dessert for dinner, and stacked pancakes are on the menu!
According to the St. Louis Beacons that published these charts (and more):
These pie charts take the individual states' percentages, split them up and then stack them. In this way, you can see how the proportion of taxes in each category collected by each state compares with the states around it.
This presentation fails our self-sufficiency test: one is completely lost if the entire data set was not printed on the chart itself.
The pie pieces apparently lost shape as they got stacked on top of each other. The top green slice labeled Tennessee represents 2.1% but look at the difference between the green Nebraska (40%) and the green Kansas (40.8%), for example.
Also, the red pieces and the green pieces are ordered on their own so that the Tennessee red is near the bottom of the stack while the Tennessee green is at the top.
This data can be shown clearly in a pair of line charts.
To really learn something about the data, we can create a scatter plot.
The exceptions are Illinois and Tennessee, and to a lesser extent, Missouri.