Extensions to DEA Models

The basic DEA models discussed in the previous chapter are associated with the way the returns-to-scale, the geometry of the envelopment surface, and the efficient projections are identified. This array of choices provides considerable flexibility, which can be further increased by incorporating refinements or extensions to the basic theory. These valuable additions to the methodology of DEA allow one to fine tune an analysis to reflect managerial or organization factors, sharpen efficiency estimates, and/or overcome inconsistencies.