Synergistic relationship between marine new-quality productivity and inclusive growth of regional marine economy

Ocean plays a critical role in advancing high-quality development. Taking into account the ongoing transformation of the marine industry, this study analyzes the defining characteristics of marine new-quality productivity, and evaluates its development level and trends in China’s coastal regions from 2010 to 2021. It then integrates marine new-quality productivity and marine economic inclusiveness within a unified framework. Using a coupling coordination degree model, the study measures the level of synergistic development between the two. Furthermore, it investigates the spatiotemporal evolution characteristics of their coordinated development through methods including kernel density estimation, standard deviation ellipse, and the Dagum Gini coefficient. The research findings indicate that: 1) During the study period, marine new-quality productivity steadily improved, exhibiting a gradient pattern characterized by “rapid progress in some leading areas, steady advancement in most regions, and catch-up efforts in a few lagging areas”. The level of inclusive growth in the marine economy also generally maintained a positive trend, with significant regional development disparities. 2) The synergistic development of the two systems showed long-term positive trends, with their coordination levels primarily transitioning from barely coordinated to primarily coordinated. However, there remains considerable room for improvement to achieve high-quality coordination. 3) The spatial evolution of the synergistic development between the two systems exhibited characteristics of “gradual disappearance of barely coordinated areas, primary coordination areas becoming dominant, and breakthroughs in moderately coordinated areas in scattered locations”. The center of synergistic development remained consistently centered on the Yangtze River Delta region, while the “stronger in the south, weaker in the north” pattern remained largely stable. 4) The Dagum Gini coefficient for the synergistic development of the two systems showed a fluctuating downward trend, with transvariation density being the main source of regional disparities. The marine economy has yet to be fully integrated into the pattern of regional coordinated development, and this integration needs to be actively advanced. Looking ahead to the “15th Five-Year Plan” period, this study provides direction for further promoting the shared benefits of the marine economy and unleashing its growth potential.