量化贸易模型：进展与挑战

中文摘要

自20世纪80年代以来，具有多国、多行业以及行业间投入产出关联特征的应用一般均衡（AGE）模型，一直是评估贸易改革影响的主要工具。我们回顾了这些模型在政策分析中的应用方式，并记录了其在预测以往贸易改革的行业层面效应方面存在的不足。我们认为，为提高模型表现，AGE模型需要纳入按行业划分的双边贸易关系产品层面数据，并更好地刻画贸易改革如何降低双边贸易成本。我们运用Kehoe等人（2015）的最少贸易产品（least-traded-products）方法，为如何改进模型提供指导。我们还就AGE模型如何吸收量化贸易理论的最新进展、以提高其预测能力并更好地量化贸易自由化带来的收益，提出了进一步建议。

Abstract

Applied general equilibrium (AGE) models, which feature multiple countries, multiple industries, and input–output linkages across industries, have been the dominant tool for evaluating the impact of trade reforms since the 1980s. We review how these models are used to perform policy analysis and document their shortcomings in predicting the industry-level effects of past trade reforms. We argue that, to improve their performance, AGE models need to incorporate product-level data on bilateral trade relations by industry and better model how trade reforms lower bilateral trade costs. We use the least-traded-products methodology of Kehoe et al. (2015) to provide guidance on how improvements can be made. We provide further suggestions on how AGE models can incorporate recent advances in quantitative trade theory to improve their predictive ability and better quantify the gains from trade liberalization.