This paper is composed of two parts. One is a survey of existing computable general equilibrium (CGE) analyses of trade policy, particularly the models used therein. Numerous surveys of trade CGE analysis already exist, but most are comparisons of simulation results, and the structures of the models are not handled very deeply. This paper takes a number of the major trade CGE models as examples, and compares the structures of the models from various angles. Of particular note is that the paper goes into great detail in explaining the imperfect competition CGE model, which has been used widely in recent years, and this should make it easy to grasp the characteristics and tendencies of the existing trade CGE models.



In addition, this paper analyzes the impact on the results of trade liberalization simulations made by the choice of models for use in the simulations. In the survey portion a comparison is made of existing CGE analyses of trade liberalization, but since the models, data, parameters, and scenarios for the existing analyses all differ, it is difficult to judge the extent to which differences between the models impact the results. Accordingly, in this paper the non-model portions are made as uniform as possible, simulations are then conducted to make comparisons of the impact of trade liberalization in various models, and an analysis is then made of how the impact of liberalization changes depending on the choice of model. For the models, one perfect competition model and eight imperfect competition models are used, and the impacts on factors such as welfare, production volume, scale of firms, number of firms, and markup rates in each model are compared. Differences in the models can be viewed as differences in the economic structures of the regions being analyzed, and therefore the analysis in this paper makes it possible to assess implications and policy connotations with regard to economic structure and to the relationship between, on the one hand, policies that can have an impact on the economic structure and, on the other, trade liberalization.