Measuring emission-reduction and energy-conservation efficiency of Chinese cities considering management and technology heterogeneity

In response to global climate change and greenhouse gas emissions, China not only is under enormous pressure to reduce emissions from all over the world, but also confronts the problem of domestic energy shortage and ecological environment deterioration. Compared with other developed countries and regions, China has implemented an extensive development model over a long period, consuming large amounts of resources and sacrificing the environment. Therefore, how to reduce emissions and conserve energy is essential for the rapid development of China. To deal with this issue, this paper proposes the improved DEA models for measuring emission-reduction and energy-conservation (EREC) efficiency. Compared with other DEA models, the models in this paper consider not only the heterogeneity of energy management in varied regions, but also the technology gap between regions. In order to assess the level of technological development in different regions, this paper proposes a new technology gap ratio index (TGR). The proposed approach is applied for measuring the EREC efficiency of 211 Chinese cities. The results show that the overall EREC efficiency of Chinese cities is low, and the central area has the lowest EREC efficiency. There is significant technology gap between the regions; the technology level is the highest in the eastern region but the lowest in the northeastern region. We also reveal that managerial and technical factors are the two main sources for the loss of EREC efficiency in Chinese cities. The specific strategies of management and technology are suggested for all cities in different areas.