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....

To allow realistic policy simulations in a changing environment, inverse demand systems must remain regular over substantial variations in quantities. The distance function is a convenient vehicle for generating such systems. While its use directly yields Hicksian inverse demand functions, those...