Integration and separation with costly demand information

We consider an industry characterized by a regulated natural monopoly in the upstream market and Cournot competition with demand uncertainty in the unregulated downstream market. The realization of demand cannot be observed by the regulator, whilst it can be privately observed at some cost by the upstream monopolist. Information acquisition is also unobservable. We study whether it is better to allow the monopolist to operate in the downstream market (integration) or instead to exclude it (separation). We show that asymmetric information on demand favours separation but unobservability of information acquisition favours integration