Environmental Efficiency Evaluation of China Based on a Kind of Congestion and Undesirable Output Coefficient

The production “congestion” phenomenon is widespread in reality although few models nowadays consider its influences. In this study, production congestion is introduced into an environmental efficiency evaluation model and a new data envelopment analysis model that considers both production congestion and undesirable output is established so as to measure environmental efficiency evaluation effectively. On this basis, we divide technological change into productive technological change and energy-savings emissionreduction technological change to establish their influences on the congestion phenomenon. The results show that productive technological change cannot relieve the degree of congestion while green technology change that stimulates environmental efficiency improvement can greatly alleviate situations of congestion.