Coordinated measurement of marine economy: High-quality and low-carbon development in China

The marine economy needs high-quality development, as severe greenhouse effect has become a global concern and carbon emission reduction has been an essential target of marine economy growth. However, a lack of synergistic research in the field of marine economy development and carbon emissions has hindered progress. This study explores the critical interactive relationship between the high-quality and low-carbon development in China's marine economy, aiming to foster green development in coastal urban agglomerations and enhance ecological security alongside economic growth. Despite the importance, comprehensive analysis across multiple dimensions of high-quality and low-carbon development of marine economy remains scarce. This paper establishes a systematic and scientific evaluation index system, utilizing text analysis technology and the Panel Vector Autoregression Model (PVAR) to quantitatively assess the complex system relationship between these dimensions. The results including: (1) The development of a 23 nodes tree structure through a bottom-up, multilevel coding method, effectively addressing the complexity of the current evaluation system for high-quality development of the marine economy. (2) Moran's I of subsystems are all negative, presenting an obvious high-low agglomeration characteristics. The discovery that intra-group differences exceed inter-group ones in marine economic development, indicates that the need for synergistic development among the provinces within marine economic circles. (3) The identification of significant bidirectional interactions between open and shared high-quality development and low-carbon development, with a notable lag effect in responses. The predominant role of innovation in all subsystems underscores the centrality of the marine innovation environment and factors as key drivers in the synergy of high-quality and low-carbon development in the marine economy.