“…The question is, would an upstream collusion still be profitable after compensating the downstream? We will focus on this question in the analysis, and ignore a related question of exactly how the compensation is done, as it is straightforward and has been studied in the literature in various forms, such as passive ownership (Hunold and Stahl, ) or transfer pricing with rationing (Schinkel, Tuinstra, and Rüggeberg, ). Consequently, our task is to identify conditions under which an upstream collusion raises the joint profits of the upstream and downstream industries.…”