Embodying Embodiment in a Structural, Macroeconomic Input-Output Model

In this paper, I develop a regression-based system of labor productivity equations which account for capital-embodied technological change and I incorporate this system into IDLIFT, a structural, macroeconomic input-output model of the U.S. economy. Builders of regressionbased forecasting models have long had difficulty finding labor productivity equations that exhibit the “Solowian” property that movements in investment should cause accompanying movements in labor productivity. The production theory developed by Solow and others dictates that this causation is driven by the effect of traditional capital deepening as well as technological change embodied in capital. Lack of measurement of the latter has hampered the ability of researchers to properly estimate the productivity-investment relationship. Recent research by Wilson (2001) has alleviated this difficulty by estimating industry-level embodied technological change. In this paper, I utilize those estimates to construct capital stocks adjusted for technological change and then use these adjusted stocks to estimate Solow-type labor productivity equations. It is shown that replacing IDLIFT’s former productivity equations, based on changes in output and time trends, with the new equations results in a convergence between the dynamic behavior of the model and that predicted by traditional (Solowian) production theory.