Examining eco-efficiency in the port sector via non-radial data envelopment analysis and the response based procedure for detecting unit segments

Recent public and governmental concerns regarding increasing greenhouse gas (GHG) emissions have drawn the attention to environmental issues in port sector literature. Since eco-efficiency improvements play a crucial role in stimulating clean production in this sector, this paper provides a comparative analysis of the eco-efficiency of twenty-four leading container ports in Europe. The exploration of the most prominent determinants of eco-efficiency and the analysis of the heterogeneity of port behaviours represent additional objectives. Further considerations derive from the assumptions on the selection of indicators that can be involved in the comparative analysis and from the involvement of GHGs in the theoretical model. Data from a sample of 52,697 active firms are considered in this empirical work. The model involves a two-step procedure: the slacks-based measure (SBM) and the response-based procedure for detecting unit segments in partial least squares (REBUS-PLS). The empirical results confirm that significant correlations emerge between the indicators considered and eco-efficiency. The findings validate that unobserved heterogeneity in the port data exists, and that REBUS-PLS allows the predictive capacity of the model to be optimised for European ports. From a policy point of view, the conclusion could offer useful insights to support policy measures targeted at the improvement of clean production.