Indifference and incomparability are different concepts that may lead to different behavioral consequences. Under the assumption that the agent is averse to making a choice between incomparable alternatives, we propose an axiomatic model that allows for a discrimination between indifference and...

This paper contributes to the axiomatization of additive rules for ranking sets of objects under the psychological principle of categorization. Firstly we proceed with the case where the elements in the sets are categorized into at most three groups, namely good (with value 1), neutral (with...

In this paper we argue, inspired by some psychological literature, that choices are the outcome of the interplay of different, potentially conflicting motivations. We propose an axiomatic approach with two motivations, which we assume to be single-peaked over a certain given dimension. We first...