A CROSSSECTION MODEL OF ECONOMIC GROWTH Paul M Sommers and Daniel B Suits T HE purpose of this paper is to present a simple threeequation model of economic growth, fitted to data covering a cross section of 100 countries compiled and published by the United Nations for the year 19661 The three dynamic equations of the model can be generally represented as follows GCFGNP I(GNPN) (1) dNN P(GNPN) (2) r G(GCFGNP, dNN) (3) Equation (1) expresses the fraction of GNP devoted to gross