Information Design with Unknown Prior
Ce Li, Tao Lin
TL;DR
This work tackles information design when the information designer does not know the receiver's prior over world states. It introduces learning algorithms that infer the unknown prior from receivers' actions over $T$ periods and then deploy robust signaling schemes that are near-optimal for the true prior. In the general case, the designer attains a tight regret rate of $\Theta(\log T)$, while in the practically important binary-action setting, a faster rate of $\Theta(\log \log T)$ is achievable and proven optimal. The methods combine a binary-search-based learning of the prior with robustification of signaling, yielding fast convergence and practical effectiveness for sequential persuasion under uncertainty.
Abstract
Information designers, such as online platforms, often do not know the beliefs of their receivers. We design learning algorithms so that the information designer can learn the receivers' prior belief from their actions through repeated interactions. Our learning algorithms achieve no regret relative to the optimality for the known prior at a fast speed, achieving a tight regret bound $Θ(\log T)$ in general and a tight regret bound $Θ(\log \log T)$ in the important special case of binary actions.
