How is the Consumer Price Index (CPI) constructed?

The Consumer Price Index (CPI) is constructed by comparing the cost of purchasing a fixed basket of goods at different times. This method involves selecting a representative set of goods and services that consumers typically buy, referred to as the "basket." The prices of these items are tracked over time to see how their total cost changes.

This approach allows economists to measure inflation by determining how much more or less consumers have to spend to buy the same basket of goods from one period to another. The CPI is a key economic indicator because it reflects changes in the cost of living and influences monetary policy, wage negotiations, and social security adjustments.

By focusing on a constant basket, the CPI provides a straightforward way to quantify the average price change experienced by consumers, making it an essential tool for understanding economic conditions.