Measuring performance and productivity of G20 Nations in the industrial sector: Enhancing environmental energy efficiency using the global Malmquist–Luenberger DEA approaches

The implementation of strategies aimed at reducing CO2 emissions and minimizing energy consumption are crucial approaches that significantly contribute to enhancing environmental energy efficiency, and the G20 countries employ a wide range of policies to foster sustainable development by promoting environmental protection, addressing social inequalities, and ensuring economic stability. This article employs the general directional DEA model to evaluate the environmental energy efficiency of the G20 nations by minimizing energy consumption, maximizing economic growth, and reducing CO2 emissions. The finding indicates that between 1997 and 2014, 31.58% of G20 countries are efficient under the Constant Returns to Scale (CRS) model, while 42.10% are efficient under the Variable Returns to Scale (VRS) model. This study also evaluates technical change and productivity growth across G20 countries between 1997 and 2014 by combining the general directional distance function technique with the Malmquist–Luenberger (ML) and Global Malmquist–Luenberger (GML) methodologies. The comparison of results of the ML and GML productivity index carries major policy implications for decision-makers in industrial sectors across G20 countries.