Restricting Multiple-Output Multiple-Input DEA Models by Disaggregating the Output–Input Vector

One of the strengths of DEA in the measurement of technical efficiency is that it readily accommodates multiple-output multiple-input production technologies. In doing so, it assumes that each of the inputs is used jointly in the production of each output. In some applied studies, this can be undesirable. We propose a new disaggregated formulation that allows a specific output to be made independent of a specific input, while maintaining the joint production relationship for the other outputs and inputs. We demonstrate the approach by applying it to measure the technical efficiency of national rail systems in 20 countries between 1990 and 1998. Copyright Springer Science+Business Media, Inc. 2005