Input-output modeling has, through the years, provided a consistent and unifying focus for IIASA's economic research. Scientists working in the Institute, first in the economic modeling task of the System and Decision Sciences area and later within the Economic Structural Change project, have cooperated extensively with colleagues throughout the world in advancing and contributing to input-output work. Perhaps the most notable aspect of these efforts has been the joint work with the INFORUM Project to develop linked systems of national models. Experience gained from the INFORUM-IIASA studies...