Date of Award
Doctor of Philosophy (PhD)
This dissertation studies strategic social influence from a theoretical perspective.
The first chapter extends Bikhchandani, Hirshleifer and Welchs 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.
The second chapter asks the following question: when a decision makers (DM) choice depends on the information provided by persuaders, does the DM benefit from that information? I address this question in the context of a Bayesian persuasion game in which independent persuaders with no private information try to persuade a DM by gathering information using verifiable tests. All persuaders want the DM to switch her action from a default action to a new action, but whether it is optimal for the DM to switch depends on the state of the world. The persuaders strategically design tests that may be biased towards the new action and that best respond to the test designs of the other persuaders. I show that although the DM never gains from the information when there is only one persuader, there always exist equilibria in which the DM strictly gains when there are more than one persuader, even if these persuaders share identical preferences towards the new action. Moreover, these beneficial equilibria always feature noisy tests that never perfectly reveal the true state. This paper shows that neither competition nor disagreement among the persuaders is necessary to facilitate a high level of information revelation in a persuasion game.
The third chapter discusses a situation in which one's consumption of a harmful tempting good (e.g., cigarettes, heroin) is affected by one's friend. Using Gul and Pesendorfer's temptation framework, I assume that having an addict as a friend makes the good more tempting. In this setting, I discuss the strategic interaction between players when they can endogenously choose friends. I show that there exist equilibria in which a player chooses a low consumption level in order to win the friendship of another. However, none of these equilibria are subgame perfect.
Chair and Committee
Mariagiovanna Baccara, Paulo Natenzon, Brian Rogers, Jonathan Weinstein,
Wu, Jiemai, "Essays on Theories of Social Influence" (2016). Arts & Sciences Electronic Theses and Dissertations. 807.