Limited factor substitutability,economic dualism,and non-saving constraints on growth

Limited substitutability has previously been defined as responsiveness of factor proportions within a certain factor-price range only, or as fixed coefficients in some sectors combined with variable proportions in others. This article explores a third definition: substitutability between some factors, combined with complementarity between those and other factors. The notion of economic dualism is thereby expanded to encompass a possible surplus not only of labor, but of any resource. The conclusion is that a non-saving constraint does not require fixed coefficients across the board, the economic dualism may therefore emerge even when commodity and factor markets are competitive.