This paper assesses cost efficiencies of Brazilian public and private companies of water supply. To measure the efficiency, we used a stochastic frontier model derived from the translog family – a specification similar to a Cobb-Douglas including a quadratic term in log output. The model...

Studies of the firm's demand for factor inputs often assume a constant rate of utilization of the inputs and ignore the fact that the firm can simultaneously choose the level and the rate of utilization of its inputs. In particular, the literature on dynamic factor demand models has, until...