In selecting sites for facilities, especially in the public sector, the issue of equity is becoming increasingly important. Beginning with the work of Mumphreys et al., McAllister, and Savas, a substantial literature has developed that incorporates equity in facility siting decision models. Despite this level of interest, however, there has been little agreement in these models as to how equity should be measured. Further, except for some recent works, there has generally been little comparison of alternative measures, or assessment of their relative value, let alone any consensus on the best measure(s) to use. Perhaps even more surprising is the great number and variety of measures employed. The motivation for this paper is to address these problems and provide for researchers a base from which issues of equity can be included in facility siting models. More specifically, we seek to review the equity literature as it pertains to facility location, assemble the set of measures that have been developed, and introduce a framework and common notation for organizing them. We also will discuss approaches that can be used to select an appropriate measure of equity.
