1.1. Pre Ziminary remarks Input-output analysis is one of the most extensively used tools of economic science. It has been introduced by Leontief (1941) who assumed that inputs into a production process of a particular sector of economic activity is a constant fraction of the output of that process in physicaZ terms. National account statisticians, however, record the inputs and outputs of sectors of economic activity in money flows. If those flows were voZumes (evalu ated at constant prices, pertaining to a certain base year) they could represent the physical amounts Leontief dealt with....