技术进步与效率追赶对农业用水效率的空间效应研究

Research on spatial effects of technological progress and efficiency catch-up on agricultural water use efficiency

本文基于2007—2015年中国省际面板数据,运用全局DEA方法测算了全要素农业用水效率,并利用Global-Malmquist指数法分解得到各省技术进步指数和效率追赶指数;分别在地理邻接、地理距离和地理经济距离嵌套三种空间权重矩阵下运用空间面板Durbin模型估计技术进步、效率追赶对农业用水效率的空间效应。研究发现:技术进步和效率追赶均对本省农业用水效率有显著的提升作用,且前者对提升农业用水效率的促进作用更大;技术创新的外部性使得其他地区的技术进步对本省农业用水效率存在显著的正向空间溢出效应,而且溢出效应并不仅仅发生在邻接省份之间,地理因素对于溢出效应发挥的作用要比经济因素的作用大;其他地区的效率追赶行为对本省农业用水效率的空间溢出效应并不显著。区域层面的实证结果表明:在东部地区,其他省份的技术进步对本省的空间溢出效应显著为正,而效率追赶引发的竞争冲击则会对本省农业用水效率产生显著为负的空间溢出效应;在中部地区,技术进步在地理距离邻近的溢出模式下能产生显著为正的空间效应,其他省份的效率追赶行为对农业用水效率的空间溢出效应则不显著;在西部地区,在邻近地区间经济发展水平相似的情况下,其他省份技术进步会对本省农业用水效率产生显著的正向空间溢出效应,效率追赶的间接效应则不显著。这意味着,要想全面、长期地提高农业用水效率,应加强农业生产、农业节水的科技支撑,加大节水灌溉等农田水利设施的投入;推进地区之间农业技术交流和农业生产的相互协作;在农业技术交流和生产协作过程中,应采取因地制宜、多样化的交流和协作模式,充分优化技术的扩散途径;邻近地区应适当差异化发展,避免过度竞争带来的效率损失。

Based on provincial panel data in China （2007-2015）, the agricultural total-factor water use efficiency has been calculated by global data envelopment analysis, and provincial technical progress change index and efficiency catch-up index have been decomposed by Global-Malmquist index method. Spatial effects of technological progress and efficiency catch-up on agricultural water use efficiency are estimated by using the spatial panel Durbin model and the matrix of three spatial weights including spatial neighbor relation, geographical distance and economic distance. The results are as follows： technical progress and efficiency catch-up both have a significantly increasing role on local agricultural water use efficiency, and the former is more important to increase the agricultural water use efficiency than the latter; technical progress of other regions has a significantly positive spatial spillover effects to the local agricultural water use efficiency owing to the externality of technical innovation, and the effects are not just happening to the neighbor provinces. And geographical factor has a more important spillover effect than economic one has; the efficiency catch-up of other regions does not have significant spatial spillover effects to the local agricultural water use efficiency. Besides, the paper analyzes the relationship between technical progress, efficiency catch-up and agricultural water use efficiency from eastern, central and western regions in China. Some conclusions show as follows： in the eastern region, technical progress of other provinces has positive spatial spillover effects to the local agricultural water use efficiency, while the competition caused by the efficiency catch-up has negative spatial effects to the local agricultural water use efficiency; in the middle area, technical progress has a significantly positive spatial effect to the local agricultural water use efficiency under the spillover model of the neighbor geographical distance, but efficiency catch-up of other provinces does not have significant spatial spillover effect; in the western region, under the condition of similar economic level among neighbor regions, technical progress of other provinces has a significantly positive spatial spillover effect to the local agricultural water use efficiency, but the indirect effects from efficiency catch-up is not significant. Based on the above, if agricultural water use efficiency needs a long-term increase, we should increase technical support of promoting agricultural technical progress and the input of farmland water conservancy facilities, promote the collaboration about inter-regional agricultural technical communication and production, apply suitable and diversified models of communication and collaboration, optimize the technical diffusion channels, and choose an appropriate differentiated development path in the neighbor areas to avoid the efficiency loss caused by excessive competition.