Back-casting consumer price index

The paper attempts to back-cast the Consumer Price Indices (CPI) for the period prior to 2011 (the year in which the index was introduced). The CPI baskets have some items, which are common to both WPI and CPI baskets. Indicesfor these items were predicted using the indices behavior of WPI and their inherent fluctuations and trends. And the indices for remaining items were predicted using their own inherent behavior only. Aggregation of the predicted indices based on these two types of indices gives the back-casted series of CPI.