Whither Armington Trade Models?

The Armington trade model distinguishes commodities by country of origin, and import demand is determined in a separable two‐step procedure. This framework has been applied to numerous international agricultural markets with the objective of modeling import demand. In addition, computable general equilibrium (CGE) models commonly employ the Armington formulation in the trade linkage equations. The purpose of this paper is to test the Armington assumptions of homotheticity and separability with data from the international cotton and wheat markets. Both parametric and nonparametric tests were performed, and the empirical results reject the Armington assumptions. This has important implications for international trade modeling and CGE modeling.