The Consumer Price Index (CPI) tracks the monthly change in prices paid by American consumers. The CPI is calculated by the Bureau of Labor Statistics (BLS) as a weighted average of prices for a selection of products and services that is indicative of total consumer spending in the United States. One of the most widely used indicators of inflation and deflation is the CPI. The producer price index (PPI), which tracks changes in the prices paid to US producers of goods and services, has a different survey methodology, pricing sample, and index weights than the CPI report.