Energy efficiency and congestion assessment with energy mix effect: The case of APEC countries

To save energy and improve the environment has become a general consensus in the whole Asia-Pacific Economic Cooperation region. This study focuses on the issue of energy congestion which has been considered as one of the key factors influencing energy efficiency. We employ a two stage Data Envelopment Analysis model to assess the energy efficiency and congestion of Asia-Pacific Economic Cooperation countries from 1995 to 2013. It is worth pointing out that the model takes undesirable outputs into account and is able to recognize energy mix effect on energy congestion. There are some discussions which based on the empirical results. It indicates that energy congestion has led to almost 20 percent of energy waste in Asia-Pacific Economic Cooperation countries. The conclusions are as follows: in general, energy efficiency of developing countries is lower than that of developed countries. Besides, energy congestion mainly comes from fossil energy use. However, the congestion of non-fossil energy shows a rising trend in recent years. In addition, a multiple liner regression analysis indicates that energy consumption and industry value added per GDP have positive effects on energy congestion, and GDP per capita has negative effect on energy congestion. At last, we promote several policy recommendations to improve energy efficiency.