Public Inputs and Productivty in the Agricultural Sector: A Dynamic Dual Approach

This paper introduces a dynamic model of productivity measurement based on recent endogenous growth theories. The model presented in this study is based on dynamic duality theory and incorporate public goods (public capital and R&D) as external factors to the firms. It also rationalizes the provision of public inputs by a benevolent social planner that internalizes the effects of them. Moreover, the Le Chatelier principle is extended for this dynamic duality modelin which the public factors are quasi-fixed for the firm and all firm-specific inputs can be adjusted in the long run. Therefore, increasing returns to scale over all inputs can still be tested at the long-run equilibrium perceived by the firm. Additionally, this model permits deriving testable hypotheses related to the two conditions of endogenous growth theory mentioned above. The model is tested with data for the U.S. agricultural sector.