The wholesale price index numbers indicate the general condition of the national economy. They measure the change in the prices of products produced by different sectors of an economy. The wholesale prices of major items manufactured or produced are included in the construction of these index numbers.
The federal bureau of statistics has been constructing and releasing the wholesale price index (WPI) in the USA since 1961 – 1962. The list of wholesale items consists of four major groups:
- Fuel, lighting and lubricants
- Manufactured products
- Raw materials