Introduced by Banker, Chames and Cooper (1984), this model measures technical efficiency as the convexity constraint ensures that the composite unit is of similar scale size as the unit being measured. The resulting efficiency is always at least equal to the one given by the CCR model, and those DMUs with the lowest input or …

# Category: Frequently Asked Question

## Pareto-efficiency/Pareto-Koopmans efficiency:

Simply stated, a unit is Pareto-efficient when an attempt to improve on any of its inputs or outputs will adversely affect some other inputs or outputs. Formally, Chames et al (1981) consider a DMU to be 100% efficient only when ‘none of its inputs can be decreased without either (i) decreasing some of its outputs, …

## Technical efficiency

An efficiency measure that ignores the impact of scale-size by comparing a DMU only to other units of similar scale. Technical efficiency is computed using the BCC model. Overall efficiency is sometimes referred to as technical efficiency as closely follows the concept of technical efficiency developed by Farrell (1957), which technical efficiency as defined here, …

## Piecewise linearity

An efficiency frontier is piecewise linear when the underlying production function is approximated through interconnected linear segments. The basic DEA models are all piecewise linear. See Chames et al (1981) for implications. [Chames A, Cooper W W and Rhodes E (1981), ‘Evaluating program and managerial efficiency: an application of data envelopment analysis to program follow …