Characteristics and Structures of Production Possibility Set Corresponding to WY Model

WY model has been proven to be an efficient method for congestion and returns to scale in data envelopment analysis (DEA). One economic application of the WY model is characteristics of empirical production possibility set. In this paper, we apply techniques and methods of transferring a polyhedral cone from its intersection form to its sum form, to identifying an intersection representation of the production possibility set corresponding to WY model. Then we give the characteristics of weak efficient surface and weak production frontier of production possibility set with intersection form. The structures of weak efficient surface and weak production frontier are also discussed. Numerical example is provided for illustration.