Symmetrically multilateral-bargained allocations in multi-sided assignment markets

We extend Rochfords (1983) notion of symmetrically pairwise-bargained equilibrium to assignment games with more than two sides. A symmetrically multilateral-bargained (SMB) allocation is a core allocation such that any agent is in equilibrium with respect to a negotiation process among all agents based on what every agent could receive -and use as a threat- in her preferred alternative matching to the optimal matching that is formed. We prove that, for balanced multi-sided assignment games, the set of SMB is always nonempty and that, unlike the two-sided case, it does not coincide in general with the kernel (Davis and Maschler, 1965). We also give an answer to an open question formulated by Rochford (1983) by introducing a kernel-based set that, together with the core, characterizes the set of SMB.