very > cf WP:USA

The United Nations Development Programme Report 2005 ranks income the United States as the 74th most equal out of 124 countries, as measured by the Gini coefficient. The richest 10% make 15.9 times as much as the poorest 10%, and the richest 20% make 8.4 times as much as the poorest 20%. (See List of countries by income equality.)

Ou, pour être plus convaincant, voici une image. Le coefficient de Gini mesure la répartition des richesses dans un pays.

http://en.wikipedia.org/wiki/Image:World_Map_Gini_coefficient_with_legend_2.png

Et pour être vraiment clair :

America's poverty line, defined for a family of four as an income of less than $19,157, is at 12.7% of the general population. Approximately one out of every five children in the United States grows up below the official poverty line. Among racial groups; Native Americans and Alaska Natives have the lowest median income while Asians have the highest. Regionally, the southern states have the lowest median incomes while the West Coast and New England have the highest.