Digital economy, green innovation, and high-quality development of the marine economy: evidence from China’s coastal regions

Abstract

This study examines the association between the digital economy and high-quality marine economic development using panel data for 11 coastal provincial-level regions in China from 2014 to 2023. Composite indices of digital economy development (DIG) and high-quality marine economic development (MEHD) are constructed, and two-way fixed-effects and panel threshold models are used to examine the overall association and its variation across development conditions. The MEHD index captures selected dimensions of marine economic development and is narrower in scope than a sustainable blue economy. The baseline estimates show a statistically significant positive association between DIG and MEHD under conventional province-clustered inference. Multiple checks also yield positive results, but the association does not reach conventional significance levels after accounting for the small number of regions. Green patent application intensity is measured as the number of green patent applications per CNY 100 billion of regional GDP. The existence of a threshold receives statistical support only at the 10% level. Conditional on the estimated threshold, the DIG coefficients are positive in both regimes, with a larger point estimate in the high-intensity regime. Cross-group tests do not reject coefficient equality across regions, periods, or income groups, whereas the urbanization-group difference is significant under conventional province-clustered inference (p=0.027). With only 11 provincial clusters, the threshold and urbanization findings provide exploratory evidence of conditional differences. The study provides provincial evidence on digitalization and high-quality marine economic development, informing context-sensitive approaches to marine-sector digitalization, green innovation, and regional governance that seek to align economic development with environmental sustainability.