This paper first demonstrates that two-stage technologies together with Lewbel's modifying function framework can provide a general procedure for combining profit functions and nominal value-added functions to obtain new specifications of GNP functions suitable for empirical trade analysis....

Limited data means that prior structure is needed when working with large demand systems. The cost function is a convenient vehicle for generating demand systems incorporating such structure. While the cost function directly yields Hicksian demand functions they will not usually have an explicit...