Using nonparametric, production-frontier methods, we decompose labor productivity growth into components attributable to technological change (shifts in the world production frontier), technological catch-up (movements toward or away from the frontier), and physical and human capital accumulation (movements along the frontier). We find that (1) technological change is decidedly nonneutral, (2) productivity growth is driven primarily by physical and human capital accumulation, (3) the increased international dispersion of productivity is explained primarily by physical capital accumulation, and (4) international polarization (the shift from a unimodal to a bimodal distribution) is brought about primarily by efficiency changes (technological catch-up).