On a related note, take a look at the US's gini coefficient, which measures income inequality (and strong predictor of social unrest): http://www.theatlantic.c

On a related note, take a look at the US's gini coefficient, which measures income inequality (and strong predictor of social unrest): http://www.theatlantic.com/international/archive/2011/09/map-us-ranks-near-bottom-on-income-inequality/245315/ http://www.theatlantic.com/international/archive/2011/09/map... http://en.wikipedia.org/wiki/Gini_coefficient http://en.wikipedia.org/wiki/Gini_coefficient