We look for the scale effects on growth predicted by some theories of trade and growth based on dynamic returns to scale at the national or industry level. The increasing returns can arise from learning by doing, investment in human capital, research and development, or development of new products. We find some evidence of a relation between growth rates and the measures of scale implied by the learning by doing theory, especially total manufacturing. With respect to human capital, there is some evidence of a relation between growth rates and per capita measures of inputs into the human capital accumulation process, but little evidence of a relation with the scale of inputs. There is also little evidence that growth rates are related to measures of inputs into R&D. We find, however, that growth rates are related to measures of intra-industry trade, particularly when we control for scale of industry.