This paper presents an application of the Generalised Error Correction Model (GECM) for heterogeneous factor demands based on the quadratic cost function. Using data for 26 West German manufacturing industries over the period 1976-1995, it turns out that less general specifications such as the...

We present a new method for imposing and testing concavity of a cost function using asymptotic least squares, which can easily be implemented even for cost functions which are nonlinear in parameters. We provide an illustration on the basis of a (generalized) Box-Cox cost function with six...