1. For full presentation of this system, see W. Isard, T. E. Smith, P. Isard, T. H. Tung, and M. Dacey,General Social and Regional Theory (Cambridge: The M. I. T. Press, 1968).
2. Also, for each region, at the end of its listing of behaving units there would be a major row for the economic market of that region.
3. In this connection, see J. H. Cumberland, “A Regional Interindustry Model for Analysis of Development Objectives,”Papers of the Regional Science Association, XVII, 1966, pp. 65–94.
4. For further discussion of ecologic systems, see Eugene P. Odum,Fundamentals of Ecology (2nd edition, Philadephia, London: W. B. Saunders Co., 1959).
5. Walter Isard, Thomas W. Langford, and Eliahu Romanoff,Philadelphia Region Input-Output Study. Department of Regional Science, Wharton School, University of Pennsylvania (1959). Preliminary working papers and coefficient table are available from the Regional Science Research Institute, Philadelphia, I, II, III, mimeograph (1967).