Per capita income is often used to measure the wealth of a nation’s population, generally in comparison to others. Per capita income is the amount received by each individual, of the annual income of the country. It is reported in units of currency per year and is calculated by dividing the total personal income by the midyear population.
The USA has one of the highest per capita income figures and there are two common ways of presenting per capita income data. The PPP method stands for Purchasing Power Parity and adjusts for the cost of living in each country. The Atlas method is the second method which adjusts the figures for currency values and inflation according to different schemes.
The most common way of calculating using the PPP method is to use the USA as the base for comparing the price of a particular product. This is taken as the base because when done in this way, the figures for USA remain the same for both PPP and Atlas.