Real versus nominal value (economics)
Gross domestic product (GDP) is a measure of aggregate output. Nominal GDP in a particular period reflects prices which were current at the time, whereas real GDP compensates for inflation. Price indices and the U.S. National Income and Product Accounts are constructed from bundles of commodities and their respective prices. In the case of GDP, a suitable price index is the GDP price index. In the U.S. National Income and Product Accounts, nominal GDP is called "GDP in current dollars" (that is, in prices current for each designated year), and real GDP is called "GDP in [base-year] dollars" (that is, in dollars that can purchase the same quantity of commodities as in the base year).
International Comparison Program
The Program produces internationally comparable price and volume measures for gross domestic product (GDP). Its component expenditures are based on purchasing power parities (PPP's). The International Comparison Program holds surveys collecting price and expenditure data for the entire range of final goods and services at intervals of some few years (the last two were separated by six years). The surveys cover GDPs of countries including their consumer goods, services, government services and capital goods. The ICP tries to make different countries GDPs comparable by calculating them in PPP both currency converters and spatial price deflators.