From Traderpedia

Definition: A family of indices developed and published by the US Bureau of Labor Statistics that measures the average change over time in selling prices received by domestic producers of goods and services.

Among the categories of goods and services covered are raw materials, intermediate phases of production, and finished goods. These indexes serve as an indicator of inflation.

PPIs measure price change from the perspective of the seller. This contrasts with other measures, such as the Consumer Price Index (CPI), that measure price change from the purchaser's perspective. Sellers' and purchasers' prices may differ due to government subsidies, sales and excise taxes, and distribution costs.