In Data Envelopment Analyses (DEA) of fossil-fuel electricity generating plants, the most common input measures are installed generator capacity (as a proxy for capital), number of employees (as a proxy for labor), and BTUs of fuel (as a proxy for energy). However, these three inputs cannot be...

Data Envelopment Analysis (DEA) applications frequently involve nonsubstitutable inputs and nonsubstitutable outputs (that is, fixed proportion technologies). However, DEA theory requires substitutability. In this paper, we illustrate the consequences of nonsubstitutability on DEA efficiency...