The wholesale price index numbers indicate the general condition of the national economy. They measure the change in 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 wholesale price index (WPI) in USA since 1961 – 1962. The list of wholesale items consists of four major groups.
- Fuel lighting and lubricants
- Raw material