<p>Several studies have compared the agency model and the conventional wholesale model and have shown that shifting from the wholesale model to the agency model increases retailers’ and consumers’ surplus and may also increase social welfare. Given their increasing power, retailers and platformers, including online shopping malls, content distribution services, and video-sharing services, have gained the power to set the price for both upstream suppliers and downstream consumers. This study considers a wholesale model in which a platformer can set prices for both supplier and consumers; we call this the new wholesale model. We construct a theoretical model to compare the new wholesale model with the agency model. Setting a wholesale price equal to the supplier’s marginal cost is the most profitable for the platformer, and we call this model the new wholesale model with marginal-cost wholesale price. However, platformers will be concerned that shifting from the agency model to the new wholesale model with marginal-cost wholesale price may violate antitrust laws. If in the shift from the agency model to the new wholesale model, the platformer ensures that it does not reduce—and that it can even increase—the supplier’s original profit in the agency model, then this shift can be accepted by the supplier and will not violate antitrust laws. We refer to this as the “new wholesale model with wholesale-price compensation.” We find that shifting from the agency model to a new wholesale model with price compensation may increase the surpluses of the supplier, the platformer, and the consumer; therefore, the total surplus also increases.</p>