A manufacturer contracting secretly with several downstream competitors faces an opportunism problem, preventing it from exerting its market power. In an infinitely repeated game, the opportunism problem can be relaxed. We show that the upstream firm's market power can be restored even further...

Considering a vertical structure with perfectly competitive upstream firms that deliver a homogenous good to a differentiated retail duopoly, we show that upstream fixed costs may help to monopolize the downstream market. We find that downstream prices increase in upstream firms' fixed costs...