中文摘要：

目前能源环境约束下的中国钢铁工业绿色转型问题受到了学术界越来越多的关注。本文构建了考虑非期望产出的网络SBM—DEA模型。从铁前工序和铁后工序两阶段视角测算了2009-2013年中国钢铁企业绿色技术效率．重点探讨了环境规制强度对绿色技术效率的影响。测算结果显示．钢铁企业整体的以及铁前和铁后工序阶段的绿色技术效率均呈现倒U型曲线特征。从生产流程的角度看．铁前工序阶段在效率挖掘方面潜力相对更大；从区域分布的角度看，东、中、西部地区钢铁企业的绿色技术效率依次递减。进一步的实证分析结果表明．当前的环境规制强度与绿色技术效率之间的负相关关系并不显著．资源循环利用率与绿色技术效率之间的正相关关系也不显著，未能观测到环境保护、资源循环利用与企业产出增长“双赢”的效果。然而，研究结果也表明研发投资率可以显著促进绿色技术效率增长。因此，在加强环保监管力度的前提下，提高环境规制强度、增加环保投入及自主研发投入是中国钢铁企业绿色技术效率提升可咨考虑的重要途径。

英文摘要：

The green transformation of iron and steel industry under the restriction of energy and environment causes great concern in theoretical circles. This paper proposes the undesirable network SBM-DEA model and measures the overall and two-stage green technical efficiencies of 37 iron and steel enterprises in China during the period of 2009--2013 from the perspective of pre-iron stage and post-iron stage. And we mainly examine the impact of environmental regulation intensity on the overall green technical efficiency. The efficiency measurement results show that： both the overall and two-stage green technical efficiencies showing the inverted-U type curve feature. There is more efficiency improvement potential in the pre-iron stage from the perspective of production process. The overall green technical efficiency of iron and steel enterprises in eastern, central and western area is decreasing in turn from the perspective of regional distribution. Furthermore, the empirical analysis results indicate that the environmental regulation intensity have a non-significant negative influence on the overall green technical efficiency, and the positive correlation between resources recycling rate and the green technical efficiency is not significant. In other words, it cannot bring the win-win opportunities of simultaneous improvements in the output increase and environmental performance and the resources recycling utilization. However, the results also manifest that the R＆D investment rate can promote the green technical efficiency growth significantly. Therefore, it is concluded that under the premise of strengthening environmental supervision, enforcing the environmental regulation intensity, increasing the investment of environment protection and independent R＆D is the crucial way of accelerating overall green technical efficiency increase significantly.