Like Cowen, Lane Kenworthy asks the question:
If we look across the rich nations, it turns out that there is no relationship between changes in income inequality and changes in the absolute incomes of low-end households. The reason is that income growth for poor households has come almost entirely via increases in net government transfers, and the degree to which governments have increased transfers seems to have been unaffected by changes in income inequality. (For more detail, see my piece [pdf] in the November-December issue of Challenge.)