Developed countries are those with higher levels of development based on GDP/capita, human development and living standards. Luxembourg was ranked highest in the world over 2008-12 using the World Bank’s measurement of GDP/capita with the equivalent of $US107, 476.
http://data.worldbank.org/indicator/NY.GDP.PCAP.CD
Norway is ranked highest using the UN’s Human Development Index (HDI). The HDI gives greater weighting to health and education than the ranking based just on GDP/capita.