Total-factor water efficiency of regions in China

Water is a limited and unevenly distributed resource in China, with the per capita amount of water resource there only about one-fourth of the world's average. However, water is an essential resource for people's lives and economic development. Over the past two decades China has seen the fruit of its rapid economic growth; nevertheless, a severe water shortage is behind this prosperous scenario and is becoming worse. Efficient water supply is certainly essential for the sustainable development of human beings. This paper analyzes water efficiency by incorporating water as an input as well as using conventional inputs such as labor employment and capital stock. An index of a water adjustment target ratio (WATR) is established from the production frontier constructed by data envelopment analysis (DEA) including water as an input. The water efficiency of regions is obtained from a total-factor framework with both residential and productive water use. A U-shape relation is discovered between the total-factor water efficiency and per capita real income among areas in China. The central area has the worst water efficiency ranking and the total adjustment amount of water used there is around three-fourths of China's total. More efficient production processes and advanced technologies need to be adopted in the central area to improve its water efficiency, especially for its productive use of water.