The wheat trade model is one of the three models in the trade modeling system developed, updated, and maintained by the Center for Agricultural and Rural Development (CARD). The other two commodity trade models are for feed grains and the soybeans complex. The three trade models are linked through cross-price linkages in the supply and demand components of these models, yet each model can be solved on a stand-alone basis. 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.
Devadoss, S.; Helmar, Michael D.; and Meyers, William H., "The World Wheat Trade Model: Specification, Estimation, and Validation" (1990). CARD Technical Reports. 7.