The high-quality development level assessment of marine economy in China based on a “2+6+4” framework

The marine economy needs high-quality development, as severe marine pollution has become a global concern and threatens human health worldwide. In the light of this, this study discusses the high-quality development of marine economy from 2006 to 2020 in 11 Chinese coastal provinces. Based on discussing the connotation and system operation mechanism of the high-quality development, this study builds a bidirectional multi-index comprehensive evaluation framework of “2+6+4” to measure the high-quality development of China's marine economy. It includes six development principles of “innovation, coordination, greenness, openness, sharing and security” and the four systems of “marine economic system, marine resource and environmental system, marine social system and marine institutional system”. The entropy method is used to measure the comprehensive evaluation index, and the Kernel density estimation reveals the evolutionary trends and spatially unbalanced characteristics. Furthermore, the causes of the regional disparities are analyzed using the Dagum Gini coefficient. The results show that China's high-quality marine economic development level shows a steady improvement trend in both the connotation and system dimensions. It has formed a spatial disequilibrium pattern with Shandong and Guangdong as the two poles. From the perspective of the formation of regional disparities, improving the marine institution system and security levels are significant breakthroughs to reduce the differences. This study assists relevant decision-making departments in gaining an in-depth understanding of the high-quality development of China's marine economy and the outstanding contradictions. Some effective measures (e.g., targeted regional coordinated development strategy and implement preferential policies) are suggested to achieve high-quality development. Further, this evaluation framework is applicable to assess the other complex system worldwide that involve multiple factors, and the findings can help other countries improve their marine economy.