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
There are many natural economic reasons for GDP-per-capita to vary between jurisdictions (e.g. places rich in Oil & Gas reserves tend to have high GDP-per-capita figures). However, it is increasingly being recognized that tax havens, or corporate tax havens, have distorted economic data which produces artificially high, or inflated, GDP-per-capita figures. It is estimated that over 15% of global jurisdictions are tax havens (see tax haven lists). An IMF investigation estimates that circa 40% of global FDI flows, which heavily influence the GDP of various jurisdictions, are described as "phantom" transactions.