Evaluating the Coupling Coordination Degree of Sustainable Marine Economic Development: Evidence from Coastal Provinces in Indonesia

Sustainable marine economic development depends on the balanced integration of economic, social, and environmental dimensions. However, empirical evidence on the current degree of coordination among these dimensions remains limited, particularly in maritime countries. This study assesses the Coupling Coordination Degree (CCD) among these three dimensions of sustainable marine economic development in 15 Indonesian coastal provinces selected based on a proportion of coastal villages exceeding the national average and availability of complete 2024 data. Using subsystem performance scores derived from a previously published Grey Relational Analysis (GRA) index, the study evaluates how balanced the current coordination state is across provinces. The findings show that higher coordination is associated not only with higher subsystem performance but also with the relative balance among dimensions. Provinces with relatively balanced development tend to achieve higher coordination, whereas strong performance in a single dimension does not necessarily lead to a well-coordinated development system. Conversely, high coordination may also arise from uniformly low performance across all dimensions, indicating that coordination and development performance represent distinct characteristics of sustainability rather than interchangeable concepts. These findings demonstrate that CCD complements conventional performance-based assessments by capturing the degree of integration among multiple development dimensions. The study contributes to the sustainable marine development literature by providing a more comprehensive framework for evaluating multidimensional sustainability and offers insights for designing integrated, place-based blue economy policies that better align economic growth, social inclusion, and environmental conservation.