Gross National Product and Gross Domestic Product is the total value of the finished goods and services produced in the economy. It is not a precise measure of national economic well-being but expressed in volume (adjusted for inflation) it is the closest single number we have got to such a measure. It is the sum of final expenditures; Export of goods and services, Imports of goods and services, Private Consumption, Government Consumption, Gross Fixed Capital Formation and Increases/Decreases(-) in stocks. The difference between Gross National Product and Gross Domestic Product is the Net Factor Income/Payments abroad. Stocks and flows are measured according to their exchange value i.e. the value at which flows and stocks are in fact, or should be, exchanged for cash. Market prices are thus ESAs basic reference for valuation.