区域贸易协定环境条款深度对出口的影响——来自“一带一路”沿线国家的证据

Impact of the depth of environmental provisions of RTAs on exports:evidence from countries along the Belt and Road

区域贸易协定中纳入环境条款有利于保护环境,但同时也可能会抑制贸易自由化,如何在保护环境的同时促进贸易发展值得深入研究。该研究利用1995—2018年“一带一路”沿线67个国家签署生效的区域贸易协定和双边出口数据,根据TREND数据库对环境条款的分类,创新性地构建并量化了三种环境条款深度指标,构建了高维固定效应模型,采取PPML估计法实证检验了这些环境条款深度对出口的影响。研究结果表明:①环境条款总深度、核心深度和执行力均对出口贸易有显著的抑制作用,且具有执行力的环境条款深度对出口的抑制作用更大。②在考虑了潜在的内生性问题及重新度量核心解释变量、划分样本区间等一系列稳健性检验后依然成立。③异质性分析发现,提高环境条款深度对“南-北”和“北-南”型“国家对”之间的出口、“肮脏”产品出口份额的抑制作用显著,但其具体条款对出口贸易的影响存在较大差异。④机制检验表明,环境条款深度主要通过提高生产成本和抑制技术创新来抑制出口。⑤进一步扩展分析发现,以数量衡量的环境条款各深度变量与出口之间呈倒“N”型关系,成员国国内环境规制差距会强化环境条款深度的出口抑制作用。该研究为促进“一带一路”沿线国家贸易发展和环境友好、高质量建设“一带一路”倡议提供了政策启示:“一带一路”沿线国家在未来签署新的RTA或现有RTA的升级谈判中可适当提高环境条款深度,发挥环境条款的“创新补偿效应”,同时还要积极拓展区域贸易协定,优先考虑经济发展水平相似的国家,在未来贸易协定谈判中重点考虑RTA环境条款的具体条款类型。

The inclusion of environmental provisions in regional trade agreements is conducive to protecting the environment,but it may also inhibit trade liberalization.How to protect the environment and promote trade development deserves further study.This paper used the regional trade agreements signed and entered into force as well as bilateral export data from 67 countries along the Belt and Road from 1995 to 2018,and innovatively constructed and quantified three indicators of the depth of environmental provisions according to the classification of environmental provisions in the TREND database.The study also constructed a high-dimensional fixed-effect model and empirically tested the impact of the depth of these environmental provisions on exports by PPML estimation.The results showed that:①The total depth,core depth,and enforcement of environmental provisions had a significant inhibitory effect on export trade,and the depth of environmental provisions with enforceability had a greater inhibitory effect on exports.②This conclusion was still valid after considering potential endogenous problems and conducting a series of robustness tests,such as re-measuring core explanatory variables and dividing sample intervals.③Heterogeneity analysis found that increasing the depth of environmental provisions only significantly inhibited exports in the samples of‘South-North’and‘North-South’countries and the export share of dirty products,but the impact of specific clauses on export trade varied greatly.④Mechanism testing showed that the depth of environmental provisions inhibited exports mainly by increasing production costs and inhibiting technological innovation.⑤Further extended analysis showed that there was an inverted-N relationship between the depth of environmental provisions measured by quantity and exports,and the gap in domestic environmental regulations in member countries would strengthen the export inhibition effect of environmental provisions.This paper provides policy implications for promoting trade development and environmentally friendly and high-quality construction of the Belt and Road Initiative in countries along the Belt and Road.These countries can appropriately increase the depth of environmental provisions in future negotiations for signing new RTAs or upgrading existing RTAs,and give full play to the‘innovative compensation effect’of environmental provisions.At the same time,they should actively expand regional trade agreements,give priority to countries with similar economic development levels,and focus on the specific clauses of RTA environmental provisions in future trade agreement negotiations.