The feed-grains trade model is one of the three models in the world trade modeling system developed, updated, and maintained by the Center for Agricultural and Rural Development (CARD). The other two commodity trade models are for wheat and the soybeans complex. The three world models are related through cross-price linkages in the supply and demand components of these models, yet each model can be solved independently. In general, however, all three trade models are solved iteratively to obtain a simultaneous solution. Equilibrium prices, quantities of supply and demand, and net trade are determined by equating excess demands and supplies across regions and explicitly linking prices in each region to a world reference price.
Helmar, Michael D.; Devadoss, S.; and Meyers, William H., "The World Feed-Grains Trade Model: Specification, Estimation, and Validation" (1991). CARD Technical Reports. 28.