A price index (plural: "price indices" or "price indexes") is a normalized average (typically a weighted average) of price relatives for a given class of goods or services in a given region, during a given interval of time. It is a statistic designed to help to compare how these price relatives, taken as a whole, differ between time periods or geographical locations. Some notable price indices include: * Consumer price index * Producer price index * Wholesale price index * Employment cost index * Export price index * Import price index * GDP deflator