The indicator is calculated as the ratio of real GDP (GDP adjusted for inflation) to the average population of a specific year, where GDP is expressed in millions and population is expressed in thousands. Real GDP is published without decimals. GDP measures the value of the total final output of goods and services produced by an economy within a certain period of time. It includes goods and services that have markets (or which could have markets) and products which are produced by general government and non-profit institutions. It is a measure of economic activity and is commonly used as a proxy for the development in a country’s material living standards. However, it is not a complete measure of economic welfare. For example, GDP does not include most unpaid household work. Neither does GDP take account of negative effects of economic activity, like environmental degradation.