This paper discusses measurement of the elasticity of substitution between goods from different countries. To remedy potential endogeneity problems in regression estimations, we use the instrumental variables (IV) approach, and the Feenstra method that does not require the use of instruments. The commodities that we study here and for which we were able to find relevant instruments are bovine, swine, and poultry meat imports by Japan. We find that the two approaches yield very similar results for these commodities. Further, upon extracting the implicit IVs of the Feenstra method, we find them as useful as the external IVs for measuring the aggregate of foreign commodities with a fixed effects regression and for estimating the foreign-domestic substitution elasticity possibly for each commodity.