摘要
鉴于中国原木进口需求弹性的参数值信息有限,利用月度时间序列数据构建中国原木进口需求函数,在Johansen协整框架下展开计量分析。向量误差修正模型的估计结果显示:中国原木的进口需求对所有变量都是缺乏弹性的,且在1%的统计水平上显著;中国国内经济产出和实际进口价格的弹性分别为0.86(±0.05)和-0.68(±0.15),短期对长期均衡的偏离的调整系数为0.61。基于估计参数的预测结果显示,受经济新常态的影响,2020年中国原木进口量约为5067万m3~6464万m3,并呈现平稳增长的态势。
⑴ Background——To evaluate the effects of trade measures on China's log import and forest resources,the elasticity of China's log import is a critical parameter. However,the quantitative information on this parameter is still limited. Previous literature mainly adopted the yearly data to estimate the elasticity. Couple literature used monthly data to estimate the elasticity, but some key variables, such as macroeconomic development,have been neglected. This paper aims to fill these gaps.⑵ Methods——The import demand model is derived from the framework of the classical production theory with Cobb-Douglas technology,where the import demand is determined by the relative import price and macroeconomic development. Monthly data is collected between January 2000 and December 2013(168 observations). Three dummy variables are included in the empirical model. The ADF test,DF-GLS test and KPSS test were chosen to investigate the stability of the variables. The Johansen method is employed to test the existence of cointegration. Finally,a vector error correction model is used to study the short-run dynamics in the relationship between the variables.⑶ Results——The ADF,DF-GLS and KPSS tests show that all the variables are treated as I(1) in the present paper,since there is insufficient evidence to support they are I(0). The Johansen test suggests that these variables are cointegrated. All the explanatory variables are in line with the theoretically expected signs,and are statistically significant at a 1% level. The magnitude indicates that there is an inelastic effect on China's aggregate imports for logs. More specifically,the elasticity of macroeconomic development is 0. 86,which implies that a 1% increase in the GDP leads to a 0. 86% increase in China's import demand for logs. In contrast,a 1% increase in the real log price would decrease the import demand by 0. 68%. All other things being same,China's import demand for logs would decline by around 25% in the month of the Spring Festival and 10% in the month
出处
《林业经济问题》
北大核心
2018年第1期69-74,共6页
Issues of Forestry Economics
关键词
原木进口
月度数据
弹性
Johansen协整
向量误差修正
China's log imports
monthly data
elasticity
Johansen cointegration
vector error correction model
