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...

Consumers increasingly prefer to bundle their purchases into a single shopping trip, inducing complementaries between initially independent or substitutable goods. Taking this one-stop shopping behavior into account, we show that slotting fees may emerge as a result of a rent-shifting mechanism...