The total market value of goods and services produced within a nation during a given period (usually 1 year). More: The components of GDP are consumption, gross investment, government purchases of goods and services, and net exports. GDP differs from GNP (Gross National Product) because GNP also includes income arising from investment and assets owned abroad. Per capita GDP is calculated by dividing the total Gross Domestic Product for a country by the number of people who live there. This allows comparison of GDP figures for different countries, taking into account population size. Gross world product is the total Gross National Product of all the countries in the world. This also equals the total Gross Domestic Product.