Dynamic factor demands and technology measurement under arbitrary expectations

We present a dynamic model of factor demands based on expected discounted c osts minimization. While making only very mild assumptions on expectations and technology, we are able to establish a duality relationship between con temporary factor demands and the technology, and we provide formula for eas ily recovering marginal products, returns to scale, and technological chang e from estimated factor demands. Parametrization and implementation are ill ustrated in a detailed example.