Efficiency and Potential of China’s Aquatic Product Exports to Belt and Road Countries: Evidence from a Stochastic Frontier Gravity Model

In the context of the sustainable transformation of the blue food system, aquatic product exports are shaped by trade scale, institutional conditions, and market access requirements. Using an unbalanced panel of China’s aquatic product exports to 39 countries along the Belt and Road from 2006 to 2023, this paper applies the BC95 one-step stochastic frontier gravity model to estimate trade efficiency and export potential. The results show that: (1) Significant trade inefficiency exists, with an average efficiency of 0.3696. (2) In the baseline model, China’s GDP, destination-country GDP and population, and common language are positively associated with exports, while geographical distance is negatively associated with exports. Political stability, government effectiveness, and trade freedom are associated with lower trade inefficiency, whereas destination-country aquatic product production and halal certification requirements are associated with higher trade inefficiency. Robustness tests broadly support the main findings, although the estimates for destination-country population, common language, and government effectiveness are more specification-sensitive. (3) A scale–efficiency matrix classifies 33 export markets into four sample-relative groups. The findings suggest that China’s aquatic product exports should shift from scale expansion toward a sustainable trade development model that places greater emphasis on efficiency, quality, compliance, and stability, with differentiated strategies across export markets.