Most previous estimates of elasticities of export demand for U.S. soybeans have emanated from single import equations subject to aggregation and simultaneous equation bias. This analysis tests U.S. soybean export data for aggregation and simultaneous equation bias and divides the aggregate data into six market equations to reduce these biases. Elasticity estimates from the six equations are compared with elasticity estimates from single equation OLS and 2SLS estimations using the same aggregate data. Results suggest that distortions from unjustified 2SLS estimation may exceed those from aggregation bias.

The demand for and supply of U.S. wheat, corn, and soybean exports is specified in a dynamic framework. Obtained results indicate differences in the export behavior of each product. U.S. corn exports are elastic, while U.S. soybean exports exhibit an inelastic response. For wheat, the derived elasticity of export demand had a positive sign. Hypothesis testing validated the dynamic structure of the estimated models in all markets. Stability properties were confirmed in export markets of corn and soybeans, but results were inconclusive for the wheat market. Adjustment coefficients indicate that exports and export prices do not adjust immediately to their equilibrium levels. Multiplier impacts indicate a stable path of convergence for all markets, with minimal impact of exogenous shocks on wheat and corn exports and export prices. Soybean export prices exhibit a significant response to changes in domestic export capacity, but minimal response to other exogenous shocks.