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.