A complete picture of the interaction between exchange rates and commodity prices requires extending existing models. A modified competitive model of global agricultural trade is extended to account for the macro-economic implications of exchange rate adjustment. Simulations of USDA's baseline forecasting system are used to create an empirical version of the theoretical model, along a survey of the literature on the macro-economic effects of exchange rate changes. Exchange rate effects on agricultural prices and U.S. trade are shown to vary with assumptions about inflation, price transmission, and multilateral exchange rate equilibrium.