Indifference, Incomparability, Indecisiveness and the Aversion to Choose.∗

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 incomparability. The rationale for this discrimination is grounded in different behavioral effects the addition of an indifferent or an incomparable alternative in a choice-set may induce. The model also allows to propose an alternative theory of choice aversion based on aversion to incomparability and to establish a behavioral distinction between the notions of incomparability and indecisiveness