Spatio-temporal differences and convergence analysis of green development efficiency of marine economy in China

As China's economy enters a new normal, the importance of the marine economy has become more prominent. To analyze its temporal and spatial evolution mechanism, we use the super efficiency EBM method to calculate the green development level of the marine economy of 11 coastal provinces and cities in China from 2006 to 2017. We first use the Kernel density estimation method to analyze the green development efficiency of the marine economy from temporal and spatial differences perspectives. We then use the panel unit root method to analyze the random convergence of the green development efficiency of the marine economy. The green development efficiency of the marine economy in Tianjin, Hebei and Hainan provinces steadily ranks in the first echelon, while Fujian, Guangdong, Jiangsu, and Guangxi are in the second echelon, Liaoning, Shandong and Zhejiang are in the last echelon. Generally, there does not exist random convergence between provinces. However, from the regional perspective, the green development efficiency in Liaoning, Shandong and Zhejiang provinces have been low for a long time. The environmental infrastructure investment has a positive radiation effect on the green development efficiency of marine economy, while the direct discharge of marine sewage is the opposite. The spillover effect of the output of marine fishing yield is negative, indicating that it has a restraining effect on surrounding provinces. Measures such as increasing investment in marine scientific research, reducing industrial sewage, strengthening fishery resource protection, and promoting industrial upgrading have a positive effect on the improvement of the green development efficiency of the local marine economy.