Productivity Differences in an Interdependent World

This paper studies cross country differences in productivity from an open economy perspective by using a Helpman-Krugman-Heckscher-Ohlin model. This allows to combine tools from development accounting and the trade literature. When simultaneously fitting data on income, factor prices and the factor content of trade, I find that rich countries have far higher productivities of human capital than poor ones, while differences in physical capital productivity are not systematically related to income per worker. I estimate an aggregate elasticity of substitution between human and physical capital that is significantly below one, clearly rejecting a world that consists of a collection of Cobb-Douglas economies and also one where Heckscher-Ohlin trade is important.