"Income Equality Is Not Only Better for Our Souls—It’s Also Better for the Economy"

"Regressive policies can also lead to financial crises. When firms suffer from global overcapacity or merely from domestic overproduction–when a glut arises of automobiles, ships, textiles semiconductors or fiber optic cable--as happened in the late 1920s and again in the earlier part of the last decade, the wealthy, joined by corporate treasurers and bankers, have tended to pour their money into speculation rather than productive investment. The financial sector has become a casino for the rich, where they have gambled away funds that could have fueled the economy. So redistributing income through tax policy isn’t just fair; it is one way to began restructuring the economy to prevent future slowdowns and crashes."  

John Judis in The New Republic explains the necessity of increased tax rates on upper incomes.