sentences:  Stochastic Frontier Analysis has also been applied in micro data of consumer demand in an attempt to benchmark consumption and segment consumers.In a two-stage approach, a stochastic frontier model is estimated and subsequently deviations from the frontier are regressed on consumer characteristics (Baltas 2005).Polacheck & Yoon (1987) have introduced a three-component error structure, where one non-negative error term is added to, while the other is subtracted from, the zero-mean symmetric random disturbance.