The improved CCR returns to scale method in DEA

When estimating returns to scale (RTS) using the Charnes, Cooper and Rhodes (CCR) RTS method in data envelopment analysis (DEA), there exist multiple optimal solutions which lead to error RTS estimation. This paper introduces the improved CCR RTS method for this problem. Given the existence of an optimal solution with Σλ* ≠ 1 in the CCR envelopment model, the existence of an optimal solution with Σλ* = 1 is the focus. A system of linear equality is constructed for the focus. And the corresponding 0-objective linear programming is also constructed to verify the feasibility of the system of linear equality. Therefore, RTS can be identified by the corresponding 0-objective linear programming and the obtained optimal solution in the CCR envelopment model.