An informed advisor wishes to convey her valuable information to an uninfor
med decision maker with identical preferences. Thus she has a current incen
tive to truthfully reveal her information. But if the decision maker thinks
that the advisor might be biased in favor of one decision and the advisor
does not wish to be thought to be biased, the advisor has a reputational in
centive to lie. If the advisor is sufficiently concerned about her reputati
on, no information is conveyed in equilibrium. In a repeated version of thi
s game, the advisor will care (instrumentally) about her reputation simply
because she wants her valuable and unbiased advice to have an impact on fut
ure decisions.