In this paper we introduce technical efficiency via the intercept that evolve over time as a AR(1) process in a stochastic frontier (SF) framework in a panel data framework. Following are the distinguishing features of the model. First, the model is dynamic in nature. Second, it can separate technical inefficiency from fixed firm-specific effects which are not part of inefficiency. Third, the model allows one to estimate technical change separate from change in technical efficiency. We propose the ML method to estimate the parameters of the model. Finally, we derive expressions to calculate/predict technical inefficiency (efficiency).
Desli, Evangelia; Ray, Subhash C.; and Kumbhakar, Subal C., "A Dynamic Stochastic Frontier Production Model with Time-Varying Efficiency" (2002). Economics Working Papers. 200315.