Fang, Lei; Li, Hecheng - In: European Journal of Operational Research 230 (2013) 2, pp. 444-446
In a recent paper by Li and Cheng [Li,S.K., Cheng, Y.S., 2007. Solving the puzzles of structural efficiency. European Journal of Operational Research 180(2), 713–722], they developed the shadow price model to solve the existing puzzles of structural efficiency theoretically. However, we...