Stochastic Production Frontiers and Decomposition of Output Growth: The case of citrus-growing farms in Tunisia

The aim of this paper is to investigate the relative contribution of technical efficiency, technological change and increased input use to the output growth of the Tunisian citrus growing farms using a stochastic frontier production function approach applied to panel data for the period 2003-2005. Knowledge of the relative contribution of factors productivity and input use to output growth and improvements in technical efficiency is crucial to provide a comprehensive view of the state of the citrus producing sector in the country and help farm managers and policy makers draw appropriate policy measures. The proposed methodology is based on the use of a flexible translog functional form. Results indicate that technical efficiency of production in citrus producing farms investigated ranges from a minimum of 11.19% to a maximum of 96.82% with an average technical efficiency estimate of 49.97%. This suggests that citrus producers may increase their production by as much as 50.03% through more efficient use of production inputs. Furthermore, the production is characterized by increasing returns to scale, which on average was 1.057. Finally, investigation of the sources of production growth reveals that the contribution of total factor productivity is found to be the main source of that growth.