Measurement and spatial convergence analysis of China's agricultural green development index

Based on the comprehensive evaluation system of agricultural green development index (AGDI), this paper uses entropy weight method and linear weighted sum method to measure the agricultural green development level of 31 provinces in China from 2013 to 2018. We then incorporate spatial correlation into the traditional convergence test model, study the spatial convergence of AGDI, and explore the reasons for regional differences in AGDI. The results show that the level of AGDI in China showed an overall growth trend during the sample survey period, but there were significant differences in the rate of AGDI among different regions, mainly manifested as "eastern > western > central." The AGDI shows a significant positive spatial correlation on the whole, and its overall spatial distribution is characterized by high-high agglomeration and low-low agglomeration. The provinces with higher and lower level of AGDI still maintain the original relatively concentrated distribution in geographical space. On this basis, the study examines the regional differences of AGDI and its evolution by Dagum Gini coefficient decomposition and spatial convergence. The results showed that the overall difference of AGDI showed a fluctuating downward trend. The intra-regional difference of AGDI in the western region was the largest, and that in the eastern region was the smallest. The contribution rate of intensity of transvariation among regions was the main source of the relative difference of AGDI. Meanwhile, the AGDI of the overall, eastern, central, and western regions present significant σ convergence and conditional β convergence. Except for the central region, the overall, eastern, and western regions present significant absolute β convergence. The low-level areas of AGDI have significant "catch-up effect" on the areas with high-level AGDI. Based on the above results, this paper also puts forward some policy suggestions from the perspective of cross-regional collaborative governance to improve China's agricultural green development mode and narrow the regional differences of China's agricultural green development.