This paper analyzes the impact of vertical integration on the static and dynamic stability of downstream incomplete collusion. It is shown that a vertical merger between an upstream firm and a downstream cartel or fringe firm promotes downstream collusion, under certain conditions on the market size. However, for low downstream market concentration, a vertical merger with a cartel firm hinders collusion. Moreover, a welfare analysis shows that consumer surplus increases with the vertical merger because the merger partially eliminates the double marginalization problem.
- Cartel stability
- Vertical integration