FUNCTIONAL FORMS OF STOCHASTIC FRONTIER PRODUCTION-FUNCTIONS AND MODELS FOR TECHNICAL INEFFICIENCY EFFECTS - A COMPARATIVE-STUDY FOR WHEAT FARMERS IN PAKISTAN

This paper considers translog and Cobb-Douglas stochastic frontiers in which the technical inefficiency effects are defined by three differe nt models. The models involved are the time-varying inefficiency model , proposed by Battese and Coelli (1992), the inefficiency effects mode l for panel data, proposed by Battese and Coelli (1995), and the non-n eutral frontier model, proposed by Huang and Liu (1994). Technical cha nge is also accounted for in the frontier models. Predicted technical efficiencies of the wheat farmers and estimates of the elasticities of wheat production with respect to the different inputs and the returns -to-scale parameter are compared under the different model specificati ons.