Gross domestic product (GDP) is a measure of the size of a countries economy. It is measured by calculating the total number of goods and services produced by a country within a given period. GDP per capita is the GDP divided by the number of people in that country, and is frequently considered an indicator of a countries standard of living. The use of GDP and GDP per capita as a measure of standard of living and economic success has been controversial as these measures do not provide an indication of other important factors. For example GDP per capita does not take into account equality, personal income or personal debt. Similarly GDP does not measure innovation, environmental record and quality of life. Instead the human development index (HDI) is often used to gage a countries quality of life and standard of living by assessing numerous factors, rather than by simply measuring the country's GDP and making assumptions.