Gross domestic product
Gross domestic product (GDP) is a monetary measure of the market value of all the final goods and services produced in a period of time, often annually 
GDP (nominal) per capita does not, however, reflect differences in the cost of living and the inflation rates of the countries; therefore using a basis of GDP per capita at purchasing power parity (PPP) is arguably more useful when comparing differences in living standards between nations.
List of countries by GDP (PPP) per capita
The gross domestic product (GDP) per capita figures on this page are derived from PPP calculations. Such calculations are prepared by various organizations, including the International Monetary Fund and the World Bank. As estimates and assumptions have to be made, the results produced by different organizations for the same country are not hard facts and tend to differ, sometimes substantially, so they should be used with caution.