森林资源与经济增长的EKC关系检验——基于省际面板数据的实证研究

Testing of the EKC Relationship between Amount of Forest Resources and Economic Growth: An Empirical Study Based on Provincial Panel Data

【目的】 检验森林资源与经济增长之间的EKC互动关系,探索维持森林资源与经济增长协同发展路径。【方法】 在环境库茨涅兹曲线理论基础上,以人均森林蓄积量为因变量、不变价人均GDP为自变量、社会经济因素为控制变量,基于1986—2015年省际面板数据,对森林资源与经济增长之间的关系进行检验,运用面板单位根和协整检验方法,构建普通EKC模型和加入控制变量的扩展EKC模型,对比分析回归结果,并寻找不同省份拐点出现的时间路径。【结果】 1) 2种类型EKC模型均支持人均森林蓄积量与经济增长的倒N形关系,人均森林资源随人均收入增长呈“下降→上升→下降”的演变过程,扩展EKC模型的拟合程度更高,其极小值和极大值拐点对应的人均GDP分别为639.79元和33 560.58元,且当前各省份处于扩展EKC的上升阶段;2) 不同控制变量对森林资源的影响作用具有差异性,技术进步、政府政策扶持与森林资源增长正相关,产业结构与森林资源增长的正相关关系不显著,而人口规模则与森林资源增长负相关,人口增长将侵占森林资源增长空间;3) 多数省份在1990年之前陆续跨过极小值拐点进入上升通道,而不同省份森林资源到达极大值拐点所需时间有差异,到达极大值拐点的时间基本与地理空间分布的经济发展水平相关,呈“东部最早、中部次之、西部最晚”的演变格局。【结论】 当前我国森林资源与经济增长处于倒N形曲线关系的上升阶段,森林资源随经济增长而增长,但森林资源的增长空间将会达到饱和,人均森林资源增长将趋于稳态,可通过继续优化产业结构、加大林业投资、引入民间资本等措施,避免各省份人均森林资源到达极大值拐点后的下滑,到达极大值拐点后要引导森林资源向质量提升转变。

【Objective】 The aim of this study was to test the interactive relationships about environmental Kuznets curve (EKC) between forest resources and economic growth, and to explore the path to maintain the coordinated development of forest resources and economic growth. 【Method】 Based on the theory of EKC, and regarded the per capita forest stock volume(pfsv) as the dependent variable, the constant price per capita GDP(pgdp) as independent variable and social economic factors as control variables, using the 1996—2015 provincial panel data in China, the relationships between the amount change of forest resources and economic growth were tested. In order to select the most appropriate regression model, the general EKC model and the extended EKC model with the control variables are constructed by using the panel unit root and cointegration test method, and find the time path of inflection point of each province. 【Result】 1) Two types of EKC model support the pfsv and pgdp present inverted N-EKC relationship, per capita forest resources along with the increase of pgdp showed the evolution process about “decline→rise→decline”, but the extended EKC model fits better, and two inflection point will reach when the pgdp reached 639.79 yuan and 33 560.58 yuan, and most provinces are in the ascent phase of the EKC curve. 2) Different control variables have different influences on amount change of forest resources, the technical progress and government investment in environmental protection are positively related with forest resources growth, and can maintain the growth of forest resources effectively, but the positive correlation between industrial structure and forest resources is not significant, while the population size is negatively related to the growth of forest resources, and population growth will encroach on the growth of the forest resources. 3) Most provinces crossed the minimum inflection point to enter the uplift channel before 1990, and the time reach the maximum inflection point between different provinces is different, which is relevant with the level of economic development on the geographical spatial, and presented as the earliest in the east, followed by the middle, the latest of the west. 【Conclusion】 It is in the rising stage of inverted N-EKC relationships between forest resources and economic growth at present. The forest resources increase with economic growth, but the growth of forest resources will reach saturation, the per capita forest resources growth will tend to be steady. Various measures can be adopted to continue to optimize the industrial structure, increase forestry investment and introduce private capital so as to avoid declining when per capita forest resources reach the maximum inflection point, and we must guide the transition to forest quality after forest quantity reach the maximum inflection point.