Returns to scale and externalities in the consumption and investment sectors

Using data on US manufacturing, I estimate internal returns to scale and external effects for the consumption and investment sectors. I construct panels of data at the industry level and use results of gross output production function estimation to derive implied estimates in a value added specification. For the investment sector, returns to scale appear to be slightly increasing, with evidence of a positive external effect. For consumption, the evidence indicates decreasing to constant returns to scale. I discuss the implications of these results for the empirical plausibility of indeterminacy in recent multi-sector models of the business cycle.