Mark T. Le Quement

job market seminar

Mark T. Le Quement

University of Bonn
Endogenous ambiguity in cheap talk
Joint with
Christian Kellner

VC Salle 205

Centre de la Vieille-Charité - Salle 205

Centre de la Vieille Charité
2 rue de la Charité
13002 Marseille

Monday, January 11 2016| 2:30pm to 4:00pm

Cecilia Garcia-Peñalosa: cecilia.garcia-penalosa[at]


This paper provides a rationale for ambiguous language, understood as language generated according to an incompletely known communication rule. We consider a cheap talk game in which a (possibly ambiguity averse) sender (S) able to randomize according to unknown probabilities faces an ambiguity averse receiver (R). We show that under fairly general circumstances, there exist equilibria featuring ambiguous (i.e. Ellsbergian) communication strategies that allow both S and R to obtain a higher ex ante payoff than any non-Ellsbergian equilibrium. Ambiguity, by triggering worse-case decision-making, allows to shift R’s response to information towards S’s favorite action. R also benefits because equilibria featuring ambiguous communication strategies involve a larger amount of information transmission.