One of the problems with choropleths is that, as explained by Hadley Wickham in this presentation, big states tend to draw more attention because of their size, but they also tend to have a low population Density. For example, Mexico City, the capital of Mexico and it’s industrial and economic center, with over 8 million people is barely visible in the map. One solution is to draw a circle in the center of each state.
The code for the chart is available from Github
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