This paper proposes a flexible stochastic cost frontier panel data model where the technology parameters are unknown smooth functions of firm- and time-effects, which non-neutrally shift the cost frontier. The model decomposes inefficiency into firm and time-specific components and productivity...

In efficiency studies using the stochastic frontier approach, the main focus is to explain inefficiency in terms of some exogenous variables and computation of marginal effects of each of these determinants. Although inefficiency is estimated by its mean conditional on the composed error term...