“…This is a common assumption in situations with multilateral contracting (e.g., Cremer & Riordan, 1987; Hart & Tirole, 1990; Horn & Wolinsky, 1988; McAfee & Schwartz, 1994, 1995; Milliou & Petrakis, 2007; O'Brien & Shaffer, 1992; Rey & Vergé, 2004, 2019). Given that in such settings multiple equilibria can arise, to obtain a unique equilibrium, following Cremer and Riordan (1987), Horn and Wolinsky (1988), O'Brien and Shaffer (1992), Milliou and Petrakis (2007), Milliou and Pavlou (2013, 2020), and Rey and Vergé (2019), we impose pairwise proofness of the equilibrium contracts; that is, we require that the contract between U and D i is immune to a bilateral deviation of U with D j . To solve the two‐stage game at each date t , we use subgame perfectness.…”