IntroductionExplaining economic growth has been a topic of interest for a long time. (1) In a multisectoral input^output framework, technological developments interact for all sectors simultaneously and induce changes in the entire matrix of input coefficients. A common method for analysing the contribution of changes in the technical coefficients to economic growth is the structural decomposition approach (Carter, 1970). (2) This method decomposes output or value-added changes, for example, into a number of key determinants, one of which is technological change, as reflected by changes in the input^output structure of the economy. Typically, however, this determinant is not decomposed further. In the present paper we aim at quantifying the underlying sources of technological change. To this end, the changes in the input^output structure are decomposed into (1) the fabrication effects in each sector, reflecting the change in its use of the intermediate input mix, (2) the average substitution of each of the products, and (3) sector-specific substitutions. It is shown that the RAS method may be used for this purpose.