EDUARDO M. OCHOA An input-output study of labor productivity in the U.S. economy, 1947-72 There has beenconsiderable attention given in the recent literature to the proposition known as Verdoon's law,particularly as formulated by Kaldor (1967). The essence of Kaldor's laws of economic growth consists of the Smithian insight thatthe expansion of the market for manufactured goods allowsfor increasing economies of scale.Thisis then seen as the "engine of growth" for the economy as a whole. Specifically, the rate of growth of manufacturing output is seen as regulating the rate of growth of manufacturing productivity, which in turn influences the rate of growth of the economy's total output. In a recent contribution by Michl (1985), therate of growth of manufactur- ing productivity was itself tied to the accumulation of capital in the classical-Marxian sense, by testing the dependence of the rate of growth of manufacturing productivity to that of the capital-labor ratio, fora pooled cross-section time-series data forOECD (Organisation for Economic Cooperation and Development) countries, with significant results. Inthis paper, we explore this relationship between productivity and mechanization within the input-output structure of theU.S. econo- my. The authoris Assistant Professor in the Department of Economics and Statistics of CaliforniaState University, Los Angeles. He would like to thankAlfred Eichner for comments on an earlier draft of the article. The article is based on results developed for the author'sdoctoraldissertation in the Economics Department of the New School for Social Research (Ochoa, 1984). Journal of Post Keynesian Economics/Fall 1986, Vol. IX, No. 1 111