空间视角下中国农业生态效率的收敛性与分异特征

Convergence and differentiation characteristics on agro-ecological efficiency in China from a spatial perspective

基于1978—2016年中国省级面板数据,采用超效率SBM模型测算省际农业生态效率,在Kernel密度估计分析时空演变格局的基础上,将空间效应因素引入经典β收敛的检验过程中,建立空间计量模型估算其空间收敛性,并分区域、分时段讨论其分异特征。研究发现:①中国农业生态效率呈现出在波动中稳定上升的"双峰"分布特征,且波峰高度的差距在缩小,但整体仍处于较低水平,农业生态效率仍存在较大提升空间,东部地区农业生态效率增长较中西部地区更加明显;②中国农业生态效率存在显著的空间收敛性,空间条件β收敛的速度为0. 105,条件收敛速度显著快于绝对收敛,空间因素对收敛趋势具有加速效应,使得地区间农业生态效率的空间差异随时间推移呈现出进一步缩小的态势;③不同地区、不同时段的农业生态效率空间收敛性同样显著,空间收敛速度呈现出东北、中部、西部、东部依次递减的分布格局,且不同地区间收敛速度均大于经典收敛,这与区域间经济发展水平、农业技术条件、基础设施、资本流动性等各方面存在关联性,而除2004—2016年外,其他时段的空间收敛速度均高于经典收敛速度,且表现出逐步递减的变化过程。由于空间收敛性的存在,各地区应充分考虑到自身资源禀赋及农业经济发展水平的差异性,邻近地区之间应加强农业生产合作与交流,并建立完备的农业生态合作机制、生态政策联动机制。

Based on the panel data of 30 provinces in China from 1978 to 2016, the supper efficiency SBM model was used to measure the inter-provincial agro-ecological efficiency (AEE) in our study. Based on analyzing the spatial-temporal evolution pattern of kernel density estimation, the spatial effect factor is introduced into the testing process of classical β-convergence, so we can estimate its spatial convergence through the spatial econometric model and discuss its differentiation characteristics in different regions and in the time interval. The results show that first the AEE in China presents a 'double-peak' distribution characteristic with stable rise in fluctuation, and the gap between peak heights is narrowing, but the overall level is still relatively low, so there is still room for improvement in AEE. Besides the AEE improvement in China's eastern region is more significant than in the central-western regions. Second, the AEE in China has a significant spatial convergence, and the rate of spatial conditions β-convergence is 0.105. The conditional convergence rate is significantly higher than absolute convergence and the spatial spillover effect accelerates the convergence, so that the spatial difference between regional AEE shows a further narrowing trend over time. Third, the spatial convergence of AEE is also significant in different regions and in different periods, and the convergence rate shows the pattern of decreasing in order of northeast China, central China, western China, eastern China. The convergence speed is higher than the classical convergence which is related to economic development between regions, agricultural technical conditions, infrastructure, capital space fluidity and so on, but the spatial convergence speed of AEE in each time interval is also higher than the classical convergence except the period between 2004-2016, and it has experienced the process of decreasing gradually. Finally, due to the existence of spatial convergence, each region should fully consider the differences of its resource endowment and agricultural economic development. The cooperation and exchange of agricultural between neighboring areas should be strengthened, and it is necessary to establish a complete agro-ecological cooperation mechanism and an ecological policy linkage mechanism.