Social Bayesian Learning in the Wisdom of the Crowd

Abstract: Being able to correctly aggregate the beliefs of many people into a single belief is a problem fundamental to many important social, economic and political processes such as policy making, market pricing and voting. Although there exist many models and mechanisms for aggregation, there is a lack of methods and literature regarding the aggregation of opinions when influence and learning between individuals exist. This is in part because there are not many models of how people update their belief when exposed to the beliefs of others, and so it is hard to quantify the dependencies between people's mental models which is essential to minimizing redundancies in the aggregation. In this paper, we explore many models of how users influence and learn from each other, and we benchmark our models against the well-known DeGroot model. Our main contributions are: 1) we collect a new dataset of unprecedented size and detail to be posted online; 2) we develop a new Social Bayesian model of how people update their mental models, 3) we compare of our model to other well-known social learning models. Specifically, we show that our new Social Bayesian model is superior to the other models tested.