Consumer Price Index

A consumer price index (CPI) is a statistical estimate of the level of prices of goods and services bought for consumption purposes by households. It is calculated as the weighted average price of a market basket of consumer goods and services. Changes in CPI track changes in prices over time. The items in the basket are updated periodically to reflect changes in consumer spending habits. The prices of the goods and services in the basket are collected from a sample of retail and service establishments. The prices are then adjusted for changes in quality or features. Changes in the CPI can be used to track inflation over time and to compare inflation rates between different countries. While the CPI is not a perfect measure of inflation or the cost of living, it is a useful tool for tracking these economic indicators. It is one of several price indices calculated by many national statistical agencies.