Practical Aspects of Value Efficiency Analysis

In this paper, we consider practical aspects for measuring Value Efficiency in Envelopment Analyis. Value efficiency is an efficiency concept that takes into account the decision maker's preferences.It was developed by Halme, Joro, Korhonen, Salo and Wallenius [1998]. The decision maker is asumed to compare alternatives using an implicitly known value function which reaches its maximum at the most preferred point on the efficient frontier. The unknown value function is assumed to be pseudoconcave and strictly increasing for outputs and strictly decreasing for inputs. The purpose of value effiiency analysis is to estimate a need to increase outputs and/or decrease inputs for reaching the indifference contour of the value function at the optimum. Because the value function is unknown, the indifference contours cannot be defined precisely. Value efficiency analysis never results in more pessimistic evaluation than in the case of a known function. To carry out value efficiency analysis, we have to locate the most preferred solution of the decision maker. In practice, this phase cannot be too complicated. We propose a few alternative ways to locate it and discuss the use of those ways in practical application.