I revisit supplier encroachment under the framework of a two-part tariff contract. When a monopoly manufacturer supplies competing retailers and each retailer's contracting process is unobservable to the rival, the retailer's lack of knowledge vis-à-vis its rival's contract may undermine the...

It is believed that market power of the input supplier, charging a linear price, is detrimental for the consumers since it creates the double marginalisation problem. We show that this view may not be true if the final goods producers can adopt strategies to reduce rent extraction by the input...