PRICE INDEX

measure of relative price changes, consisting of a series of numbers arranged so that a comparison between the values for any two periods or places will show the average change in prices between periods or the average difference in prices between places. Price indexes were first developed to measure changes in the cost of living in order to determine the wage increases necessary to maintain a constant standard of living. They continue to be used extensively to estimate changes in prices over time and are also used to measure differences in costs among different areas or countries. See also consumer price index; wholesale price index.