基于WITS-SMART模型的中国大豆进口关税调整策略研究

Research on the Adjustment Strategy of China′s Soybean Import Tariff Based on WITS-SMART Model

为研究如何弥补中美贸易摩擦导致的中国大豆进口缺口,本文利用WITS-SMART模型和HS 6分位数据,模拟了5种情景下中国对不同来源国实施大豆进口关税削减的经济效应。通过对关税削减程度的分析发现,随着关税的逐渐下降,中国对所有来源国的大豆进口都将增加,且对出口大豆规模较小国家(如加拿大、俄罗斯、乌拉圭等)的进口增长率要大于规模较大的国家。若对大豆出口中国规模较大的国家(如巴西)削减大豆关税,虽然中国福利水平会提高,但同时会面临巨额关税损失;通过对产品差异和进口依存度的研究发现,进口依存度越高,实施关税削减时贸易转移效应越小;考虑到价格效应即寡头可能会影响世界市场大豆价格,对寡头削减关税会导致贸易创造效应、贸易转移效应和进口增长率的下降,关税政策效果会打折扣。因此,对巴西、阿根廷两国短期内暂不考虑实施关税削减,而针对加拿大、俄罗斯等大豆出口中国规模较小的国家,应加快实施零关税。本研究为保障中国大豆供给稳定和构建大豆进口多元化格局提供了政策依据。

To narrow the import gap of Chinese soybean caused by sino-us trade friction,this paper examined the economic impact of import tariff reduction for China′s soybean using WITS-SMART model and HS Six-bit data.Simulations were conducted under five scenarios.Analysis of the extent of tariff reduction showed that,with the decline of tariffs,China′s soybean imports from importing countries will grow rapidly.The growth rate of import from countries with small soybean exports scale(such as Canada,Russia,Uruguay,etc.)was generally higher than that of countries with large soybean export scale.If China cuts its soybean tariffs for larger exporting countries,such as Brazil,it will face huge tariff losses even though its welfare level will increase.The examination of product difference and import dependency showed that,the higher the import dependence,the smaller the trade diversion while conducting tariff reduction.Considering the price effect,it was found that oligarchs may affect the price of soybeans in the world market and cutting tariffs for oligarchs will lead to the decline of trade creation effect,trade diversion effect and import growth rate.Consequently,there occured the loss of tariff policy efficiency.Therefore,we argued that tariff reduction should not be implemented for Brazil and Argentina in the short term,while zero tariff should be implemented for Canada,Russia and other countries with smaller soybean exports scale to China.This study provides a policy basis for ensuring the stability of soybean supply and constructing the pluralistic pattern of soybean import in China.