The conventional cost efficiency model assumes that all the input prices are fixed and known exactly at each decision making unit. In practice, however, exact knowledge of prices is difficult and prices may be subject to variations over very short periods of time. In this paper, we develop a new...

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...