A general procedure to recover the marginal products of a cost minimizing firm

In this paper we develop a new method, based on generalized inverse, to rec over the first derivatives of the production function. This allows us to re trieve returns to scale, technological progress and, in a dynamic setting, a measure of the adjustment cost. The method is general and systematic and it applies in cases where the traditional method does not. It is especially relevant when examining dynamic models or regulated firms.