Chakraborty and Harbaugh (2010) prove the existence of influential cheap talk equilibria
in one sender one receiver games when the state is multidimensional and the preferences
of the sender are state-independent. We show that only the babbling equilibrium survives
the introduction of any small degree of uncertainty about the sender’s preferences in the
spirit of Harsanyi (1973). Introducing small costs of lying as in Kartik (2009), i.e. a small
preference for sending the actual state as the message, while removing some influential
equilibria, makes others robust to payoff uncertainty. Finally, modelling a small desire
to be truthful endogenously, i.e. by taking into account how the receiver interprets the
message, may make some influential equilibria robust, but may also remove all influential
equilibria.