Efficiency measurement using a latent class stochastic frontier model

Efficiency estimation in stochastic frontier models typically assumes that the underlying production technology is the same for all firms. There might, however, be unobserved differences in technologies that might be inappropriately labeled as inefficiency if such variations in technology are not taken into account. We address this issue by estimating a latent class stochastic frontier model in a panel data framework. An application of the model is presented using Spanish banking data. Our results show that bank-heterogeneity can be fully controlled when a model with four classes is estimated. This paper was written during Luis Oreas visit to Binghamton University in the summer of 2002. We would like to thank an associate editor of the journal and two anonymous referees for their detailed comments. However, we alone are responsible for any remaining errors.