"Correlated information cascades," October 2021
Abstract: This paper extends the model of information cascade (Bikhchandani, Hirshleifer, and Welch, 1992) by introducing two correlated queues of players. By comparing the equilibrium outcomes of the two-queue game with the benchmark one-queue game, this paper finds out that the observability of correlated players decreases the probability of correct permanent cascades. (.pptx slides)
"Breaking echo chambers with personalized news," with John Nachbar May 2023
Abstract: When a digital platform such as Google News selects personalized news for its user, will it select news that conforms to its user’s bias, thus creating an “echo chamber”? To answer this question, this paper studies a game between a click-maximizing platform and a user who tries to learn the true state of the world. We derive the necessary and sufficient conditions for the user to exhibit a preference for headlines that contradict her prior bias, which induces the platform to recommend prior-contradicting headlines in equilibrium. Many classes of distributions, including the Normal distribution, satisfy these conditions. This result stands in contrast with theories of media in the literature and is consistent with recent empirical findings.
"Non-competing persuaders," European Economic Review, August 2020, volume 127, 103454
Abstract: I study Bayesian persuasion games with multiple persuaders in which the persuaders are non-competing: all persuaders want the decision maker to take the same action, regardless of the state. In the case of a single persuader, it is known from previous research that the persuader-optimal information design leaves the decision maker with no surplus. In this paper, I show that with two or more non-competing persuaders and independent tests, there are always equilibria in which the decision maker receives surplus. Moreover, if there is exogenous noise then the decision maker receives surplus in every equilibrium, provided the number of persuaders is sufficiently large; asymptotically, the decision maker learns the true state in every Pareto optimal symmetric equilibrium with infinitely many persuaders. Moreover, with sufficient exogenous noise, having more than one persuader not only improves the welfare of the decision maker but it also improves the welfare of the persuaders.
"Helpful laymen in informational cascades," Journal of Economic Behavior and Organization, August 2015, volume 116, pages 407-415
Abstract: This paper extends Bikhchandani, Hirshleifer and Welch’s informational cascade model by introducing two types of players: experts with high signal accuracy and laymen with low signal accuracy. If a small enough fraction of laymen are present in the population, the probability of having a correct cascade is strictly higher than if no laymen are present. This is because the presence of laymen makes experts less eager to follow suit, which increases the amount of private information revealed.