Cone extensions of polyhedral production technologies

In data envelopment analysis, cone extensions of production technologies are often used for the estimation of scale efficiency of decision making units. Furthermore, the non-increasing and non-decreasing returns-to-scale (NIRS and NDRS) technologies are often used for their returns-to-scale characterization. Although a number of new production technologies have recently been developed in the literature, their cone, NIRS and NDRS extensions have not always been fully explored. In this paper, we obtain general results that show how these extensions can be obtained, for an arbitrary polyhedral technology. We illustrate the usefulness of our results by examples