The
gross domestic product (
GDP) or
gross domestic income (
GDI) is one of the
measures of national income and output for a given
country's economy. GDP is defined as the total
market value of all final goods and services produced within the country in a given period of time (usually a
calendar year). It is also considered the sum of value added at every stage of production (the intermediate stages) of all final goods and services produced within a country in a given period of time, and it is given a money value.
The most common approach to measuring and understanding GDP is the expenditure method
"Gross" means depreciation of capital stock is not subtracted. If net investment (which is gross investment minus depreciation) is substituted for gross investment in the equation above, then the formula for net domestic product is obtained. Consumption and investment in this equation are expenditure on final goods and services. The exports-minus-imports part of the equation (often called net exports) adjusts this by subtracting the part of this expenditure not produced domestically (the imports), and adding back in domestic area (the exports).
Economists (since Keynes) have preferred to split the general consumption term into two parts; private consumption, and public sector (or government) spending. Two advantages of dividing total consumption this way in theoretical macroeconomics are
