Gross domestic product (GDP) refers to the market value of all officially recognized final goods and services produced within a country in a given period. GDP per capita is often considered an indicator of a country's standard of living; GDP per capita is not a measure of personal income. See Standard of living and GDP. Under economic theory, GDP per capita exactly equals the gross domestic income (GDI) per capita. See Gross domestic income.

It is not to be confused with Gross National Product (GNP) which allocates production based on ownership. Gross domestic product is related to national accounts, a subject in macroeconomics.

GDP was first developed by Simon Kuznets for a US Congress report in 1934, who immediately said not to use it as a measure for welfare (see below under limitations). After the Bretton Woods conference in 1944, GDP became the main tool for measuring the country's economy.

G.D.P can be determined in three ways, all of which should, in principle, give the same result. They are the product (or output) approach, the income approach, and the expenditure approach.

Joseph Eugene Stiglitz, ForMemRS, FBA, (born February 9, 1943) is an American economist and a professor at Columbia University. He is a recipient of the Nobel Memorial Prize in Economic Sciences (2001) and the John Bates Clark Medal (1979). He is also the former Senior Vice President and Chief Economist of the World Bank. He is known for his critical view of the management of globalization, free-market economists (whom he calls "free market fundamentalists") and some international institutions like the International Monetary Fund and the World Bank.

In 2000, Stiglitz founded the Initiative for Policy Dialogue (IPD), a think tank on international development based at Columbia University. Since 2001, he has been a member of the Columbia faculty, and has been a University Professor since 2003. He also chairs the University of Manchester's Brooks World Poverty Institute and is a member of the Pontifical Academy of Social Sciences. Stiglitz is an honorary doctor of Durham Business School, an honorary doctor at the Charles University, an honorary professor at Tsinghua University School of Public Policy and Management and a member of the Executive and Supervisory Committee (ESC) of CERGE-EI in Prague. Stiglitz is one of the most frequently cited economists in the world.