Inspection, Measurement and Interpretation of Club Convergence of Water Use Efficiency in China from 2003 to 2015

摘要

Based on Quah's (1997) analysis framework about distribution dynamics and using the extended Markov chain model and the spatial Markov chain model, this paper studies the phenomenon of club convergence of total water use, agricultural water use and industrial water use in 31 provinces of mainland China from 2003 to 2015. Firstly, it manages to inspect the club convergence of three types of water use efficiency, then measures the degree of club convergence based on the constructed club convergence index, and finally explains the phenomenon of this kind of club convergence in view of space. The results are as follows. (1) The phenomenon of club convergence exists among the three types of water use. While its convergence degree eases with time, it is still very obvious. For example, the probability that areas with low industrial water use efficiency remain low after 5 year lengths is 0.808, while that is 0.918 when it comes to high-level areas, so it is urgent that the regional water use efficiency effort should be coordinated. (2) The degree of club convergence of industrial water use efficiency is the highest among the three ones, followed by the total water use and then the agricultural water use. More seriously, some areas remain low-level for a long time and they are caught in a "low-level trap", which should be taken great consideration by the government. (3) The phenomenon of club convergence is influenced by spatial factors. On the one hand, when the water use efficiency among areas is different, the local areas tend to be influenced by the adjacent areas to some extent. Simple to say, high-level adjacent areas have positive impact while low-level ones are opposite. On the other hand, there exists a characteristic of agglomeration no matter it is among high-level districts or low-level districts in spatial distribution, so spatial spillover effect follows among different clubs. However, the positive spillover effect in high level clubs is much larger than that in low level clubs, which incurs greater difference between high-low-level clubs so as to promote the phenomenon of club convergence. This is particularly evident in the club convergence of industrial water use in China.