Analysis of Regional Disparities, Spatiotemporal Evolution and Key Influencing Factors of Marine New Productive Forces in China

New productive forces are the new impetus for the high-quality development of the marine economy. To accurately measure the development level of marine new productive forces, this study constructs an evaluation index system from four aspects: development impetus, development structure, development mode, and development achievements. This study determines the combination weights of indicators based on relative entropy. Kernel density estimation, spatial Markov chain and Dagum Gini coefficient are used to analyze the spatiotemporal evolution, regional disparities and sources of marine new productive forces in coastal provinces of China. Finally, the decision-making trial and evaluation laboratory together with interpretative structural modeling (DEMATEL-ISM) is used to analyze the key influencing factors of marine new productive forces. Results show that the marine new productive forces have been increasing year by year, but the overall level is relatively low. There is a phenomenon of “club convergence” in the development level of marine new productive forces, and the state transfer occurs between adjacent types. The overall variation in marine new productive forces is showing a downward trend, with disparities arising mainly from inter-regional variation and hypervariable densities. The key influencing factors include investment in marine R&D, the openness of foreign investment, the openness of foreign trade, and investment in pollution control. The study conclusion provides support for designing a development path for marine new productive forces that conforms to regional characteristics.