ECO-EFFICIENCY AS AN OPERATIONAL MEASURE Although the concept of eco-efficiency was first introduced and discussed in the literature by Schaltegger and Sturm (1990), it gained popularity only after the publication of the book entitled Changing Course by Schmidheiny (1992). Some other aspects of the concept and its limitations have been elaborated by Gladwin et al. (1995). In practice the term ‘eco-efficiency’ is used to convey different meanings with little precision. To begin with, therefore, it is important to clarify the concept of the term as it applies to the corporate level.