WPU084101's base is 1982 = 100; the industry series PCU321920321920 uses December 2003 = 100. Index levels with different bases can't be compared directly; only percentage changes can.
In a contract, the "base month" is something else: the month whose index value matches the agreed starting price.
See also
- Producer price index (PPI)
- A U.S. Bureau of Labor Statistics measure of the change over time in prices domestic producers receive.
- Escalator clause
- A contract term that adjusts price in line with a published index.
- Cost per trip (CPT)
- The total cost of using a pallet for one shipment, including everything beyond its price.