Does an Ecological Industry Chain Improve the Eco-Efficiency of an Industrial Cluster? Based on Empirical Study of an Energy-Intensive Industrial Cluster in China

An energy-intensive industrial cluster is a combination and integration of energy-intensive industries formed by ecological industry chains. Eco-efficiency may reflect the effect of ecological industry chains in an energy-intensive industrial cluster. To evaluate the eco-efficiency of energy-intensive industries, industry chains, and industrial clusters with different level of eco-industry chains, the eco-efficiency is decomposed into two dimensions of resource efficiency and environment efficiency. The eco-efficiency evaluation index system and models of energy-intensive industries are constructed to analyze the eco-efficiency using a two-dimensional three-layer matrix framework, including energy-intensive industries, ecological industry chains, and industrial clusters. This paper presents an empirical and comparative analysis based on data from the chemical industry, building materials industry, metallurgy industry, and thermal power industry from 2004 to 2015. The results show that the eco-efficiency of energy-intensive industry, energy-intensive industry chains, and energy-intensive industrial clusters are all on the rise. The eco-efficiency of energy-intensive industrial clusters and energy-intensive industry chains are obviously higher than that of any single energy-intensive industry. This finding indicates that the ecological industry chains of an energy-intensive industrial cluster have improved the eco-efficiency. In recent years, the effect of ecological industry chains and network construction has been significant, but not tight enough.