sustainability Article A Study on the Sustainable Performance of the Steel Industry in Korea Based on SBM-DEA Yongrok Choi 1,* ID , Yanni Yu 2 and Hyoung Seok Lee 1,* ID 1 Global E-Governance Program, Inha University, Inharo100, Nam-gu, Incheon 402-751, Korea 2 Institute of Resource, Environment and Sustainable Development (IRESD), Jinan University, Guangzhou 510632, China;
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[email protected] (H.S.L.); Tel.: +82-32-860-7760 (Y.C.); Fax: +82-32-876-9328 (Y.C.) Received: 1 November 2017; Accepted: 8 January 2018; Published: 12 January 2018 Abstract: Since South Korea has implemented its emissions trading scheme (ETS) in 2015, several studies have explored the sustainable performance of ETS in terms of production efficiency. However, few studies focused on Korean company-level data in their model. Thus, this study focuses on data from firms in the steel industry, which is a representative greenhouse gas emitter. Based on the slack-based measure (SBM) approach, we find the following implications: First, this paper evaluates both environment energy efficiency (EEE) and traditional energy efficiency and discovers that the efficiency value, in general, is overestimated, when greenhouse gas emissions are ignored. EEE still shows a decreasing efficiency value over time, implying that strong regulation is needed to increase efficiency. Second, this paper provides the return to scale status of decision-making units in the steel industry, through decomposing EEE. Results show that many steel firms are in the state of increasing returns to scale, so they can enhance their efficiency by increasing their scale.