While coping with nonsphericality of the disturbances, standard GMM suffers from a blind spot for exploiting the most effective instruments when these are obtained directly from unconditional rather than conditional moment assumptions. For instance, standard GMM counteracts that exogenous...

This paper analyzes theoretically and empirically how upstream markets are affected by deregulation downstream. Deregulation tends to increase the level of uncertainty in the upstream market. Our theoretical analysis predicts that deregulated firms respond to this increase in uncertainty by...