Energy and environmental performance evaluation of China's non-ferrous metals industry from the perspective of network structure

As an energy-intensive industry, the energy and environmental issues of non-ferrous metals industry receive increasing attention. Dividing the production of non-ferrous metals into two sub-stages including mining and processing (M&P) and smelting and pressing (S&P), a non-cooperative game network data envelopment analysis model with double viewpoints (optimistic and pessimistic) is developed to evaluate the energy and environmental efficiency of China's non-ferrous metals industry. Moreover, we construct a novel network Malmquist productivity index to identify the dynamic evolution of energy and environmental performance. The results of 25 provinces over 2010–2017 show that energy and environmental efficiency of China's non-ferrous metals industry is very low during the study period, and the efficiency gap of two sub-stages increases significantly over time. Additionally, the energy and environmental efficiency in eastern region is more affected by the M&P sub-stage, while the efficiency of that in central and western regions is greatly influenced by the S&P sub-stage. Technical progress plays a key role in the productivity improvement of the M&P sub-stage, but the main driving force of productivity change in the S&P sub-stage is different in the three regions. Based on above findings, several targeted policy implications are suggested to prompt the sustainable development of China's non-ferrous metals industry.