The greater the disparity in wealth between the very rich and everyone else, the more unstable an economy becomes. Our nation has now created a larger gap in the distribution of wealth than the massive chasm that helped fuel the Great Depression.
In 1928, one year before the global economic collapse, the wealthiest .001% of the U.S. population owned 892 times more than 90% of the nation’s citizens. Today, the top .001% of the U.S. population owns 976 times more than the entire bottom 90%. This is not sustainable, and makes for a very volatile economy. It would appear that the American empire is about to crash.
http://www.thenation.com/image/extreme-inequality-chart