In this note, I provide an axiomatic characterization of the relative utilitarian bargaining solution to Nash bargaining problems. The solution is obtained when Nash’s independence of irrelevant alternatives axiom is replaced by the weak linearity axiom, while retaining the other three axioms. RU maximizes the sum of proportional gains, or, equivalently, minimizes the sum of proportional losses. RU is scale invariant and compared to the Nash and Kalai and Smorodinsky solutions, it is ex ante efficient when the bargaining problem is (...) considered as a lottery of future bargaining problems. (shrink)

The first-order condition of the Nash bargaining solution equates the ratio of utilities to the ratio of marginal utilities. It turns out that this common ratio plays a role in determining whether the Nash solution, roughly speaking, is “more utilitarian” or “more egalitarian.” More specifically, I propose a sense of proximity to utilitarianism and/or egalitarianism according to which, in bargaining problems with distinct utilitarian and egalitarian points, the Nash solution is closer to utilitarianism if the aforementioned ratio is smaller than (...) one, and closer to egalitarianism if that ratio is greater than one. (shrink)

For every 2-person bargaining problem, the Nash bargaining solution selects a point that is “between” the relative utilitarian point and the relative egalitarian point. Also, it is “between” the utilitarian and egalitarian points. I improve these bounds. I also derive a new characterization of the Nash solution which combines a bounds property together with strong individual rationality and an axiom which is new to Nash’s bargaining model, the sandwich axiom. The sandwich axiom is a weakening of Nash’s IIA.