Global variation of outputs with respect to the variation of inputs in performance analysis; generalized RTS

Returns to scale (RTS) is an important topic in performance analysis, which helps managers to make decisions about the expansion or contraction of the operation of the DMU under assessment. But the RTS classification of DMUs gives only partial information, because it is a local notion. In this paper we extend the concept of RTS and we seek the precise relation between the proportional variation of outputs and the proportional variation of inputs. An approach is provided, which is able to determine this relation based on the parametric analysis and perturbation in linear programming.