There are various ways to classify countries as "developed" or "developing." One method considers the Human Development Index, income levels (World Bank data), and inclusion in the IMF's list of developed countries.

Countries meeting all three criteria are unequivocally classified as developed. Those meeting two out of three criteria (HDI and income) include a diverse group like wealthy Gulf states (e.g., Saudi Arabia, UAE), Chile, Uruguay, Poland, and some Balkan countries. In contrast, certain Balkan nations only fulfill one criterion, either in income or HDI.