Modeling international trade flows and market shares for agricultural commodities: a modified Armington procedure for rice

The Armington procedure (AP) has become increasingly popular in agricultural trade analyses. However, some arguments have arisen concerning the relevance of using the procedure for such analyses. This study examines the assumptions commonly made when using the Armington procedure and suggests modifications for agricultural trade analyses. Results from models utilizing rice-trade suggests that the assumptions of the single constant elasticity, in particular, may not be appropriate for analyzing trade. These results also suggests that, with proper modifications, the AP can be applied to agricultural trade. Further, results of a modified Armington procedure indicate that trade in rice exports is highly competitive and that changes in market shares of individual exporters are not independent of changes in budget expenditure allocated to imports.