[Above] is what [Alan Krueger, the chairman of the Council of Economic Advisers] dubs the Great Gatsby Curve. On the horizontal axis is the Gini coefficient, a measure of inequality. On the vertical axis is the intergenerational elasticity of income — how much a 1 percent rise in your father’s income affects your expected income; the higher this number, the lower is social mobility.
As he shows, America is both especially unequal and has especially low mobility. But he also argues that because we are even more unequal now than we were a generation ago, we should expect even less social mobility going forward.