In this paper, we show that the order of magnitude of the finite sample bias of the GMMld^{(2)} estimator of Bun and Kiviet (2006) can be reduce from O(T/N) to O(1/N) if the optimal weighting matrix is used. To demonstrate this result, we consider a model transformed by the upper triangular...

This paper uses a sectoral version of the conventional Imperfect substitutes model to motivate a parsimonious estimation of trade elasticities. The elasticities we compute depend directly on the specialization of trade across sectors, which is believed to add econometric precision to our...