“In order to maintain continuity in the time series data on Index of Industrial Production (IIP), it is imperative to provide a linking factor so that the new series, when released, may be compared with the outgoing one. As a matter of policy, the Central Statistics Office (CSO) does not prescribe or recommend to data users any particular method of linking, for conversion of index figures from one series to another. The choice of the method to link various index series is left to be decided by the users. The CSO has been using the arithmetic conversion method. According to this method, the linking factors for conversion of indices from the base 2004-05 series to the earlier base 1993-94 and from the base 1993-94 to the base 1901-81 up to Sectoral level are as follows:

The CSO does not convert the indices at further disaggregate level. The users are to satisfy themselves regarding the conversion factor they calculate. The CSO does not check / correct / verify any conversion factor or converted index figures done by any user / researcher.”