This contribution analyses a market with an upstream bottleneck monopoly and a downstream activity that may either be vertically integrated or separated. Separation always reduces the consumer surplus, and the total surplus unless there are large cost reductions. Downstream competition from a public or private network monopoly would crowd out other firms, also when public ownership is associated with more modest objectives than welfare-maximisation. A market is therefore less likely to remain a mixed oligopoly than without vertical relations. However, private firms would survive in a moderately welfare-improving mixed oligopoly with cross-subsidisation and access charges equal to marginal costs.
- Vertical separation