ABSTRACTThe purpose of this paper is to analyze whether major results from Mankiw, Romer, and Weil (1992) cross national study on productivity convergence hold when applied to U.S. states where there is more uniformity of institutional factors and homogeneity of the economic data. Similar to the international studies, this paper identifies the contribution of factor inputs and human capital by state for the period 1969–88. The study finds a strong tendency for convergence even when controlling for other factors, with human capital growth being most important; the speed of convergence is roughly twice as high as between countrie