Product Mix in the Output Matrix of Indian Economy

In practice it is seen that for a given classification of commodities and industries, commodities are produced not only as characteristic or principal products but also as industrial by-products and/or commodity joint products. In other words, industries produce, along with its principal products, principal products of other industries, and output matrix, instead of being identity matrix (as in standard case) becomes rectangular with non-zero off-diagonal elements. On the other hand information on cost structure is available not for individual commodities produced in the economy but for individual industries. Presence of product mix in the industry output matrix thus deprives us of information on input cost structures of individual commodities.