In terms of commodity prices, the issue relates to the choice of price index and RBI has to depend on those which are readily available. In India, there are two sets of indices, viz., wholesale price index (WPI) and consumer price indices (CPIs). The latter is based on occupational classification and category of residence (rural or urban).
Four broad measures of CPIs are available at the national level to capture prices of a defined basket of goods and services consumed by a particular segment of the population : (i) CPI for Agricultural Labourers (CPI-AL); (ii) CPI for Rural Labourers (CPI-RL); (iii) CPI for Industrial Workers (CPI-IW); and (iv) CPI for Urban Non-Manual Employees (CPI-UNME).