affluence in the united states blue-collar worker bourgeoisie classless society creative class economy of the united states educational attainment in the united states gentry gold-collar worker green-collar worker household income in the united states income inequality in the united states lower middle class lumpenproletariat middle class nobility nouveau riche old money parvenu peasant personal income in the united states petite bourgeoisie pink-collar worker proletariat ruling class salary serfdom slavery social class social stratification underclass united states department of commerce upper class upper middle class white-collar worker working class