基于双边进口需求弹性的中美经贸摩擦福利损失测算

Calculation of Welfare Losses from Sino-US Economic and Trade Frictions Based on Bilateral Import Demand Elasticities

近期中美经贸摩擦不断升级,加征关税重新成为贸易保护的手段,关税保护及其福利效应再次成为学界研究热点。本文将估算进口需求弹性的方法推广到双边层面,利用123个国家或地区2000-2016年HS6进口品数据,对双边进口需求弹性和贸易限制指数进行估算,并重点评估了中美经贸摩擦的福利损失。结果显示:中国总体进口需求弹性平均值为-1.79。基于双边弹性和关税测算的贸易限制指数值低于利用多边关税测算的值,这表明已有文献高估了中国的贸易保护程度。此外,中美经贸摩擦可使中美贸易顺差下降975.45亿美元,同时使中美两国无谓损失分别增加25.70亿美元和79.49亿美元。情景模拟显示,中国对美国加征关税时未完全考虑关税结构,美国征税改善贸易不平衡的边际效应在下降。

With the recent continuous escalation of Sino-US economic and trade frictions,increasing tariffs have become a means of trade protection.Tariff protection and its welfare effects have therefore once again become research hotspots.This paper expands the method of estimating import demand elasticities developed by Kee et al.(2008)at the bilateral level,estimating China's bilateral import demand elasticities and the trade restrictiveness index by using HS-6 import products data from 123 countries from between 2000 and 2016,and focusing on assessing welfare losses from the Sino-US economic and trade frictions.The results of this paper show that:①the overall average elasticity of Chinese imports is-1.79,and the value of trade restrictiveness indices based on the bilateral elasticities and tariffs estimate is lower than the estimate using multilateral tariffs,indicating that the literature has overestimated the extent of China's trade protection;②Sino-US trade frictions have caused the Sino-US trade surplus to fall by US$97.55bn,while increasing the deadweight losses of China and the United States by US$2.57bn and US$7.95bn respectively;and③scenario simulations show that China does not fully consider the tariff structure when tariffs are imposed,while the marginal effect of the increased trade imbalance caused by the United States'tariff increase is declining.