A computable general equilibrium analysis of the welfare effects of trade liberalization under different market structures

Using a static world computable general equilibrium model with 16 sectors and 14 regions, this paper compares welfare effects of trade liberalization of the perfectly competitive model and eight imperfectly competitive models. Our main findings are as follows. First, the size of the welfare impact systematically depends on the type of model. Second, the welfare impact of the perfectly competitive model is not necessarily smaller than those of imperfectly competitive models. Third, the integrated market model tends to have a larger welfare impact than the segmented market model. Fourth, the model with the fixed number of firms tends to have a small welfare impact. Finally, the variety effect tends to have a stronger influence on the welfare effects of liberalization than do scale and markup effects. 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 derive policy implications with regard to the relationship between economic structure and trade liberalization.