经济增长与环境保护协同共进:基于贸易政策不确定性下降的污染减排效应视角

Coordinating Economic Growth and Environmental Protection:From the Perspective of the Emissions Abatement Effect of the Decline in Trade Policy Uncertainty

随着生活水平的提高,人们对于环境质量需求日益增长,导致经济增长与环境保护之间的矛盾凸显。本文提出了一个贸易政策不确定性下降影响企业污染排放的理论分析框架,选取大气污染中的二氧化硫、工业烟尘、工业粉尘、工业废气以及水体污染中的代表化学需氧量五种污染物构建微观企业环境绩效指标体系,将2002年中美建立永久正常贸易关系(Permanent Normal Trade Relations,PNTR)视为一次拟自然实验进行双重差分估计。研究发现:除工业废气外,贸易政策不确定性下降显著降低了企业其他四种污染物的排放强度,该结论在考虑一系列影响因素后依然成立;机制分析表明,贸易政策不确定性下降主要通过技术效应和配置效应降低企业污染物排放强度,而以扩大企业产出规模、提高企业污染物排放量为特征的规模效应并不存在;异质性分析发现,贸易政策不确定性下降的污染减排效应在高污染物排放强度企业、出口企业、非技术密集型行业以及高工业化水平城市更加突出;基于新近数据的扩展分析发现,随着外部贸易政策不确定性加大,国内制造业上市企业污染物排放强度有所上升。本文研究结论表明,维持开放、稳定的贸易政策有利于经济增长与环境保护协同共进,这为当前中国实现经济稳步增长目标和打好污染防治攻坚战提供了政策启示。

Economic growth and environmental protection are important issues for a nation.Behind China’s world-renowned economic achievements,the problem of environmental pollution is becoming more and more prominent,leading to the intensified contradiction between economic growth and environmental protection.Take air pollution for example.According to the 2022 Bulletin on the State of Ecology and Environment in China,the proportion of cities at the prefecture level and above across the country where the concentration of air pollutants exceeded the standard stood at 37.2%.In China,industrial emissions constitute the primary source of air pollution,so reducing pollutant emissions from the industrial sector is key to realizing China’s green development goals.Further,clarifying the factors affecting industrial pollution emissions is the basis for advancing pollution control.Existing literature studying the factors influencing industrial pollution emissions focuses on perspectives such as declining trade barriers,foreign investment liberalization,import competition,and environmental regulation,with little attention to the impact of changes in trade policy uncertainty on enterprises’pollution emissions.This paper proposes a theoretical analytical framework for how the decline in trade policy uncertainty affects enterprises’pollution emissions,selects five pollutants such as sulfur dioxide(SO2)and chemical oxygen demand(COD)to construct a microcosmic enterprise environmental performance indicator system,and treats the establishment of permanent normal trade relations(PNTR)between China and the United States as a quasinatural experiment to perform difference-in-difference estimation.The research results are as follows.(1)With the exception of industrial exhaust,reduced trade policy uncertainty significantly reduces enterprises’emissions intensity for the other four pollutants,and this finding remains valid when a variety of influencing factors are considered.(2)The decline in trade policy uncertainty reduces the pollutant emissions intensity of enterprises mainly through the technology effect and the allocation effect,while the scale effect,characterized by expanding the scale of enterprises’output and increasing enterprises’pollutant emissions,do not exist.This is because that decline in trade policy uncertainty can both increase enterprises’output and reduce their pollutant emissions.Thus,maintaining an open and stable trade policy is conducive to synergizing economic growth and environmental protection.(3)The pollution abatement effect of the decline in trade policy uncertainty is more remarkable for enterprises with high pollutant emissions intensity,export enterprises,non-technology-intensive industries,and cities with a high industrialization level.(4)With the increase in trade policy uncertainty,the pollutant emissions intensity of domestic listed manufacturing enterprises will rise significantly.The above findings provide the following policy insights for China to achieve the goal of steady economic growth and effective pollution control.(1)The government should firmly safeguard diversified and stable international economic and trade relations and build a diversified international trade network.(2)It should tap the potential of the domestic market and develop the internal circular economy to create more development space for export-oriented enterprises with high trade dependence.(3)It should step up efforts to encourage and guide enterprises to conduct R&D,innovation and technological upgrading.It is also important to create a fair competition,stable and orderly market environment for enterprises to improve the efficiency of resource allocation.The marginal contribution of this paper is as follows.(1)From the dual perspectives of the establishment of PNTR between China and the United States and the rise of trade protectionism during the post-financial crisis period,this paper examines the impact of changes in trade policy uncertainty on the pollutant emissions intensity of Chinese manufacturing enterprises.Moreover,this paper incorporates economy and environment into an analytical framework,and evaluates the economic effect and environmental effect of the decline in trade policy uncertainty at the micro level,and enriches the literature in this field.(2)This paper constructs a theoretical analysis framework for the effects of trade policy uncertainty on enterprises’pollution emissions through the technology effect,allocation effect and scale effect.The empirical results confirm the existence of the technology effect and allocation effect,but exclude the scale effect characterized by increasing enterprises’output and pollutant emissions.(3)By selecting a variety of pollutants,this paper constructs a more comprehensive microcosmic indicator system for measuring enterprises’environmental performance,revealing the differences in the effect of the decline in trade policy uncertainty on different pollutants in enterprises.In addition,this paper fully discusses the heterogeneity of the emissions abatement effect of the decline in trade policy uncertainty from four dimensions:the pollutant emissions intensity of the enterprise,whether the enterprise exports or not,the technological intensity of the industry,and the industrialization level of the city.