The Indian Wholesale Price Index (WPI) was first published in 1902, and was used by policy makers until it was replaced by the Producer Price Index (PPI) in 1978. The Wholesale Price Index (WPI) is the index used to measure the changes in the average price level of goods traded in wholesale market. A total of 576 commodity prices make up the index. It is available on a weekly basis, with the shortest possible measurement lag being two weeks. Because of this, it is widely used in business and industry circles and in Government, and is generally taken as an indicator of the inflation rate in the economy.