Disclosure regime of contract terms and bargaining in vertical markets

We consider a vertically related market where an upstream monopolist supplies two downstream Cournot competitors. We allow the vertical contract terms to be either interim observable or secret. We address a dichotomy in the literature by endogenizing the disclosure regime of contract terms. The latter could be set via a Non-Disclosure Agreement. Firms bargain over both the disclosure regime and the contract terms. Our results indicate that when firms trade over two-part tariffs, universal interim observability is the unique equilibrium no matter the bargaining power distribution or the product differentiation. Yet, when firms trade over linear tariffs there may be a multiplicity of equilibria. We also show that under competing vertical chains we get universal interim observability as a unique equilibrium no matter the upstream structure. Our results qualitatively hold under Bertrand competition too. Our welfare analysis indicates that universal interim observability and two-part tariffs yield the highest consumer surplus and total welfare.