On the Sensitivity Matrix of the Nash Bargaining Solution

In this note we provide a characterization of a subclass of bargaining problems for which the Nash solution has the property of disagreement point monotonicity.While the original d-monotonicity axiom and its stronger notion, strong d-monotonicity, were introduced and discussed by Thomson [15], this paper introduces local strong d-monotonicity and derives a necessary and sufficient condition for the Nash solution to be locally strong d-monotonic.This characterization is given by using the sensitivity matrix of the Nash bargaining solution w.r.t. the disagreement point d.Moverover, we present a sufficient condition for the Nash solution to be strong d-monotonic.