Collective rationality in bargaining

Roth (1977) axiomatized the Nash (1950) bargaining solution without Pareto optimality. His result is considered an improvement on Nash’s original one, since it dispenses with notions of collective rationality. Several variants of Roth’s result have been obtained in a line of subsequent works. However, all of them rely on Nash’s (1950) independence axiom. Whether or how collective rationality can be dispensed with in the absence of independence remained up until the present an unexplored topic, and, in particular, no such foundation have been provided for the Kalai-Smorodinsky (1975) solution—the literature’s central non-independent solution, which, one can informally argue, is second in its status only to that of Nash. In light of this state of affairs, I do the following (i) derive efficiency-free axiomatizations of the Kalai-Smorodinsky solution, and (ii) explore the relationship between Nash’s independence and