Evaluation of energy efficiency in GCC countries: a slack-based model and bootstrap approach considering CO2 emissions

Purpose This paper aims to evaluate energy efficiency in the Gulf Cooperation Council (GCC) countries between 2000 and 2023, taking into consideration some factors that determines energy consumption level in this region. Design/methodology/approach This study contributes to the ongoing debates on energy efficiency through a nonparametric Data Envelopment Analysis (DEA) approach, based on the Slack Based Measure (SBM) model with CO2 emissions as undesirable output. Moreover, to improve the robustness of the results, the analysis was complemented with the Bootstrap-DEA approach. Findings The results showed that the average inefficiency level in the GCC region was approximately 10%, with significant variation between countries. As a second stage analysis, the fixed-effects panel data model also reveals crucial economic and environmental factors that may affect efficiency. Originality/value The novelty of this study lies in the use of SBM model, which is a non-radial DEA approach that enables the authors to identify inefficiencies with higher precision as compared to traditional radial DEA models. The SBM model enables the inclusion of CO2 emissions as a “bad output” and leads to a more accurate and realistic measure of energy efficiency, considering environmental negative externalities.