Consumer Price Index

The Consumer Price Index (CPI) measures changes over time in the general level of prices of goods and services that households acquire for the purpose of consumption.

The CPI is considered a key statistics in economic policy making. In many cases, the CPI was originally developed to measure changes in the cost of living of residents. Nowadays however, the CPI is also used as a key input for monetary policy and inflation targeting, and as a proxy for general inflation in the economy as a whole. 

CPIs are also often used in contracts as the measure to adjust payments for the effect of inflation. As a result, its measurement can have a substantial financial impact on households, private enterprises and government bodies.