An Evaluation of Port Environmental Efficiency Considering Heterogeneous Abatement Capacities: Integrating Weak Disposability into the Epsilon-Based Measure Model

As pivotal hubs in maritime logistics networks, ports bear a growing responsibility to harmonize economic activities with environmental stewardship. Evaluating and enhancing port environmental efficiency (PEE) is therefore imperative for maritime decarbonization and sustainability. However, conventional approaches often assume homogeneous abatement capacities across heterogeneous ports, which may distort evaluation results. To address this flaw, we develop a modified EBM-Undesirable model embedding weak disposability and non-uniform abatement factors, explicitly accounting for heterogeneity the in port’s abatement capabilities. Drawing on panel data from China’s major coastal ports during 2013–2022, this study further employs the Global Malmquist Index and Dagum Gini coefficient to investigate dynamic characteristics and regional disparities in PEE. Key findings reveal: (1) PEE exhibits a modest yet volatile upward trend, accompanied by pronounced inter-port divergence; (2) Total factor productivity (TFP) demonstrates sustained improvement attributable to technical efficiency advancements, yet reveals untapped potential in technological level; (3) Substantial spatial heterogeneity persists, dominated by interregional differences, though overall inequality is gradually converging. Given the observed regional disparities and technological potential, policy suggestions are proposed to advance port decarbonization, regional coordination, and maritime sustainability.