Assessing the sustainability of high-, middle-, and low-income countries: A network DEA model in the presence of both zero data and undesirable outputs

Sustainability evaluation has been an important topic for politicians and professionals for the last few decades. A data envelopment analysis (DEA) is a popular technique for evaluating the sustainability of decision-making units (DMUs). The traditional DEA models consider a DMU as black-box thus ignoring the interactions among the different processes. This study proposes a new network data envelopment analysis (NDEA) model for evaluating the sustainability of high-, middle-, and low-income countries. The proposed NDEA model allows us to evaluate sustainable production and distribution stages in a unified framework in the presence of both zero data and undesirable outputs. The results of our proposed model show that countries with high and low incomes perform well in the sustainable production stage but have a weak performance in the sustainable distribution stage. In contrast, middle-income countries have weak performance in the sustainable production stage but good performance in the sustainable distribution stage. Finally, to identify countries' strengths and weaknesses, we also did a sensitivity analysis. Based on the results, the paper proposes solutions for reducing inefficiencies in the sustainable production and distribution stages. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.