This paper addresses these gaps by asking: How do variations in technological advancement influence the sustainable efficiency of major global ports? We examine 50 leading ports worldwide over 2000–2023 using Stochastic Frontier Analysis (SFA) within a metafrontier framework, which allows efficiency to be measured relative to both group-specific frontiers and a global best-practice frontier. Within this setting, we quantify the Technology Gap Ratio (TGR) to capture the distance between group technologies and the metafrontier (Battese et al., 2004;, et al., 2008). In line with work that incorporates environmental externalities into performance analysis (Gu et al., 2025), our model embeds key sustainability factors alongside conventional inputs.
The study makes three contributions. First, it develops an Environmental Indicator (EI) that aggregates port-level practices—renewable energy use, waste management, air-quality monitoring, onshore power supply, and incident response—thus providing a composite measure aligned with international reporting. Second, it applies an SFA-based metafrontier with a flexible translog specification to capture non-linearities, factor interactions, and time-varying technological change across heterogeneous environments (Kumbhakar & Lovell, 2000; Battese et al., 2004). Third, by combining environmental and operational dimensions in a global, cross-cluster dataset, it delivers comparative evidence on where and how technological gaps constrain sustainable efficiency—thereby generating actionable insights for policy and management.
Conceptually, we distinguish between sustainable ports and green ports: the former integrate environmental, economic, and social objectives, while the latter emphasize minimizing environmental impacts through clean technologies and eco-efficient operations. This distinction matters because the technological gap—the degree to which a port’s available technology lags behind the global frontier—directly conditions its capacity to operationalize sustainability strategies at scale.
However, while the literature is rich in documenting best practices and emerging technologies, there is limited empirical evidence comparing ports across different regions and technological levels. In light of the growing environmental demands facing the maritime industry, this study sets out to explore how variations in technological advancement affect port sustainability. Specifically, it aims to measure and analyze the technological efficiency gaps across leading global ports between 2000 and 2023, using a metafrontier stochastic frontier analysis approach. The goal is to generate empirical evidence that can inform strategic decisions for advancing green port development through technological innovation.The hypothesis guiding this study is During the period 2000–2023, ports with smaller technological gaps and greater adoption of environmental technologies tend to achieve higher sustainability performance.
A sustainable port and a green port are conceptually linked: both prioritize environmental responsibility, but while a sustainable port integrates social, economic, and ecological dimensions, a green port specifically focuses on minimizing environmental impact through clean technologies and eco-efficient operations. Importantly, the technological gap between ports directly affects their capacity to implement sustainability measures; thus, closing this gap is essential for advancing the green and sustainable transformation of global port systems.
The distinctive contribution of this study lies in its methodological innovation and empirical scope. First, it proposes and applies an Environmental Indicator (EI) to quantify port-level environmental performance, using a composite of normalized sub-indicators aligned with international benchmarks. Second, it utilizes the Stochastic Frontier Analysis (SFA) to assess port efficiency in resource usage. Finally, by applying the metafrontier framework, the study enables comparative efficiency assessments across heterogeneous technological environments, thus identifying specific technological gaps.
This article is structured as follows. Section 1 introduces the study, while Section 2 reviews the relevant literature. Section 3 describes the SFA-based metafrontier methodology applied to evaluate port efficiency and technological gaps, as well as the sample, variables, and clustering criteria for the 50 ports analyzed. Section 4 presents the empirical results, including efficiency scores by cluster and a comparative assessment of performance. Section 5 discusses the findings and outlines their managerial, practical and policy implications. Finally, Section 6 summarizes the main conclusions and highlights possible directions for future research.
Delfin-Ortega, O.V. Assessing technological and sustainable performance in maritime transport through the SFA metafrontier framework. Discov Sustain 6, 1319 (2025). https://doi.org/10.1007/s43621-025-02200-x