Operational Efficiency Evaluation and Persistence Analysis for Chinese Port-Listed Companies Using the Network SBM Model

Ports play a crucial role in global maritime logistics systems, and evaluating their operational efficiency is essential for improving resource allocation. However, existing studies often treat port operations as a black box, limiting the understanding of internal mechanisms and sources of inefficiency. Using panel data from 17 Chinese port-listed companies from 2018 to 2023, this study applies a network slacks-based measure (SBM) model to evaluate operational efficiency within a two-stage framework. The service stage transforms labor, fixed assets, and berth length into cargo and container throughput, while the profitability stage converts these outputs into revenue and net profit. The results show that overall operational efficiency remains relatively low. Profitability-stage efficiency is generally lower than service-stage efficiency, indicating that inefficiency mainly arises from the limited ability to convert operational performance into financial outcomes. Significant differences are also observed across regions and operational scales. To further capture persistence, this study evaluates the dynamic performance of efficiency by considering both growth and fluctuation over time. The findings indicate that most inefficient ports exhibit weak persistence, reflecting limited capacity to maintain stable efficiency improvements. This study provides a stage-based analytical framework for identifying inefficiency sources and offers insights for enhancing both efficiency and the long-term stability of port operations.