After publishing the map on inequality in Spain, some comments have led me to think it could be interesting to show a comparative vision:

Spain: Renta personal de los municipios españoles y su distribución, Miriam Hortas Rico & Jorge Onrubia Fernández, FEDEA, 2014. Based on 2007 data

France: Les revenus et le patrimoine des menages, Cédric Houdré & Juliette Ponceau, edition 2014, INSEE. Based on 2011 data

Inequalities among European states, according to the INSEE publication

USA: State of Disparity, a Project looking at the economic disparity in CT, WSHU radio (A view from Connecticut, but with a nationwide chapter). Based on data from 2006 to 2010.

Inequality is on the rise, but with different flavors in each country.