Regional difference decomposition and policy implications of China's urban land use efficiency under the environmental restriction

Exploring the general distribution characteristics and evolution rule of urban land use efficiency (ULUE) is of great significance for the efficient integration between urban land use system and the external environment. Most of the existing literature focuses on the existence of differences in ULUE between regions of mainland China, and rarely pays attention to the measurement of the regional differences of ULUE. This study puts the indicators on environmental pollution into the evaluation index system of ULUE and employs a non-radial, non-angular model of slack-based measure (SBM) to measure the ULUE of 31 provinces across mainland China from 2001 to 2014. The results showed that the ULUE in mainland China displayed a general trend of increase in the period, with the national average level increasing from 0.7585 to 0.7989. Besides, the spatial distribution pattern drawn by ArcGIS visualization method presented significant regional differences, with generally higher ULUE in the eastern and western regions compared to the central region. On this basis, the study examines the regional differences of ULUE and its evolution in mainland China by Dagum's Gini Coefficient Decomposition and Kernel Density Estimation. The result showed that the Gini coefficient of China's ULUE presented a trend of fluctuating rise followed by a fluctuating fall, with the greatest difference in the eastern region, much greater than that in central and western regions in most years. Meanwhile, the inter-regional difference is the main source of the overall differences. The study concludes that effective measures should be taken to improve the ULUE and narrow the regional gap of ULUE.