贸易开放对中国农业面源污染成本的影响——基于动态面板系统GMM模型的实证研究

Impacts of Trade Opening-Up on the Costs of Chinese Agricultural Non-point Source Pollution--Eempirical Analysis Based on the GMM Model of the Dynamic Panel System

基于2008—2019年的宏观数据,用公式法和PEA工具法分别核算全国31省份化肥、农药、农膜和温室气体的农业面源污染成本并以此为据探究农业面源污染成本的时空差异。在这基础上,应用动态面板系统GMM模型,分区域考察农业贸易对面源污染的影响。结果显示:(1)中国农业面源污染总成本在2008—2019年间呈倒U形变化,其中化肥是影响成本变化的最主要因素。污染成本较高的地区为华北平原地区、长江中下游地区及珠江流域地区,而西部地区的污染成本较低;(2)农业贸易与农业面源污染成本总体上显著负相关,具有显著的污染治理效应;(3)东部地区的进口贸易与农业面源污染成本系数为正而中西部地区为负,而两区域出口贸易皆能改善环境,但东部地区出口的改进效应要远优于中西部地区。鉴于此应坚持对外开放,保持合理贸易结构,科学利用技术效应和结构效应改善环境,加大政府环保投入。

Based on the 2008-2019 macro data,formula method and PEA tool method were adopted to calculate the time and space differences in the costs of agricultural non-point source pollution in 31 provinces,which include fertilizers,pesticides,agricultural films and greenhouse gases.Then a dynamic panel system and GMM model investigate the regional impacts of agricultural trades on the non-point pollution.Research results reach the following conclusions.(1)The total pollution costs from agricultural sources in China manifested an inverted U-shape change between 2008 and 2019,of which fertilizer application was the most important factor.Higher pollution cost areas center on the North China plain,the middle and lower reaches of the Yangtze River and the Pearl River basin,while cost is lower in the western regions.(2)Agricultural trade is significantly negatively related to the pollution costs from agricultural sources,and has significant pollution control effects(3)The cost coefficient of imports and agricultural non-point pollution is positive in the eastern regions and negative in the central and western regions.Exports in both regions help improve the environment,but the improvement effect from exports is much better in the eastern region than that in the central and western regions.In view of this,it is important to adhere to Opening-up,maintain a reasonable trade structure,scientifically apply technological and structural effects to improve the environment,and increase government investment in environmental protection.