A Comment on Theory of Integer-Valued Data Envelopment Analysis

The mixed-integer linear programming data envelopment analysis models were proposed due to this reason that the conventional DEA models may suggest some non-integer values for the inputs and/or outputs of decision making units (DMUs) which those data can only be specified with integer values such as the number of employees and books. There are a few researches on integer-valued DEA and this paper focuses on the three previous ones. The paper characterizes some shortcomings on those researches with some mathematic logics.