Pii: S0038-0121(99)00010-5
نویسندگان
چکیده
This paper develops a necessary and sucient condition for the presence of (input) congestion. Relationships between the two congestion methods presently available are discussed. The equivalence between FaÈ re et al. [12,13] and Brockett et al. [2] hold only when the law of variable proportions is applicable. It is shown that the work of Brockett et al. [2] improves upon the work of FaÈ re et al. [12,13] in that it not only (1) detects congestion but also (2) determines the amount of congestion and, simultaneously, (3) identi®es factors responsible for congestion and distinguishes congestion amounts from other components of ineciency. These amounts are all obtainable from non-zero slacks in a slightly altered version of the additive model Ð which we here further extend and modify to obtain additional details. We also generate a new measure of congestion to provide the basis for a new uni®ed approach to this and other topics in data envelopment analysis (DEA). # 2000 Elsevier Science Ltd. All rights reserved.
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تاریخ انتشار 1999