建立無效率補償資料包絡分析法改善企業環境績效評估

Abstract

全球環境保護議題及國際企業對環境管理的重視均日益增加，建立適當的環境績效評估方法因而已是近年國內外的研究重點。資料包絡分析 (Data envelopment analysis, DEA) 法常用於分析企業績效，由於其可整合多項投入與產出指標以及不必先設定參數等優點，故常被用以評估企業環境績效。然而，企業若有少數表現較優異的績效指標，即使該企業其他績效指標表現甚不佳，仍有可能使其於資料包絡分析法中獲得相對有效率的結果。因此，本研究以一些廠商為案例，以廢棄物產生量與二氧化碳排放當量為產出指標，銷售額為投入指標，發展無效率補償資料包絡分析 (Inefficiency Countervailed DEA, IC-DEA) 法改善企業環境績效評估。本研究首先建立逆向包絡分析 (Reverse DEA, RDEA) 法，定義無效率前緣 (inefficiency frontier) 且據以判識出相對無效率之企業，進而綜合傳統DEA與RDEA結果評估企業環境績效。本研究所提出的ICDEA法可藉由考量無效率績效補償改善企業環境績效評估。

Global environmental protection and corporate environmental management have gained increasing attention in recent years. Establishing methods to assess corporate environmental performance has thus become a worldwide essential research area. Data envelopment analysis (DEA) is a method frequently used to evaluate relative firm performance because its advantages of multi-inputs and outputs can be integrated without assigning pre-defined parameters. However, high values in a few indicators can lead to a company being regarded as ‘efficient,’ despite valuing poorly in other essential indicators. Therefore, a new method called Inefficiency Countervailed DEA (IC-DEA) method is developed. For establishing the DEA and IC-DEA models, two output indicators, waste generated and eCO2 emission volume, and one input indicator, sales, are considered. The proposed IC-DEA method first defines an inefficient frontier using the proposed Reverse DEA (RDEA) model. An IC-DEA value is then determined by summing both the DEA and RDEA values. The IC-DEA method is applied to assess the environmental performance of several major companies in Taiwan. It is believed that the proposed method can significantly improve corporate environmental performance assessment.