Some lessons from the modelling of the Spanish rice market
对比了传统计量模型与专门反映西班牙大米政策影响的模型，发现政策模型更准确预测历史演变，但无法用于预测加入欧共体后的政策剧变，因此需要依赖制度分析和专家意见来理解未来。
Spanish accession to the European Comminity ( EC) will lead to many changes in Spain's agricultural sector. Predicting the nature of these changes is difficult because the new policy regime differs significantly from historic Spanish policies. In this paper, conventional econometric models of the Spanish rice sector are constrated with a model designed specifically to reflect the pervasive impact of Spanish rice policies. This policy model predicts the historical evolution of production, consumption and trade more accurately than the conventional models. However, the policy model cannot be used to predict the impact of the radical policy changes in Spain resulting from the introduction of the EC rice regime because the historical relationships no longer hold. It is argued that alternative approaches relying more on institutional analysis and expert opinion need to be developed to understand the future of the Spanish rice sector.