What is the difference between GDP or GNI (formerly GNP) data in “current dollars” and “constant dollars”?
Current dollars means “nominal” whereas constant dollars means “real.” The value of output thus can increase for two distinct reasons. It can increase because more goods and services are being produced, or it can increase because prices of goods and services have risen. To eliminate the effects of changing prices, one must compute real or constant-dollar GDP (or GNI), which values the output of various time periods with a set of fixed prices. The current-dollar or nominal GDP (or GNI) is the value of output measured in prices which existed when the output was produced.
