Luxembourg remains by far the richest country in the European Union, more than six times more affluent than the bloc''s poorest member, Bulgaria, according to an EU measure of economic output per capita. Ireland, which was second richest in the 27-nation EU in 2007 before its banking and construction boom went bust, has slipped but not far, to joint third place in 2010, according to the EU''s purchasing power standard (PPS) measure.