In this paper we propose a stochastic formulation of the materials balance condition which imposes physical constraints on production technologies. The estimation of the model involves a composed error term structure that is commonly applied in the literature on stochastic frontier analysis of...

This paper examines empirically the relationship between innovation and market structure within a simultaneous framework at the industry level of aggregation. We use a model in which R&D affects both, demand and cost conditions. An optimization process leads to optimal industry R&D expenditure...