Semiparametric Smooth-Coefficient Stochastic Frontier Analysis

Provides semiparametric smooth-coefficient stochastic frontier analysis following Sun and Kumbhakar (2013) where the coefficients of the parametric part vary smoothly with a set of nonparametric variables. Inefficiency term is allowed to depend on a set of determinants through heteroskedasticity. Smooth coefficients are estimated using nonparametric regression and the remaining frontier parameters are estimated by maximum likelihood. Technical efficiency and inefficiency are computed using the Battese and Coelli (1988) and Jondrow et al. (1982) methods, respectively. Confidence intervals for technical efficiency are computed using the approach of Horrace and Schmidt (1996) .