Ulric B. and Evelyn L. Bray Social Sciences Seminar

Abstract: Does the order and timing of information arrival affect beliefs formed within a group? We address this question by extending the DeGroot social learning model to allow for sequential information arrival. We find that the final beliefs can be altered by varying only the sequencing of information arrival, keeping the information content unchanged. We identify the optimal and pessimal information release sequences that yield the highest and lowest attainable consensus, respectively. In doing so, we bound the variation in final beliefs that can be attributed to the variation in the sequencing of information. We show that groups in which all members are equally influential are those most susceptible to information sequencing. Finally, with regard to information aggregation, as the number of group members grows, the sequential arrival of information compromises the group's beliefs: in all but particular cases, beliefs converge away from the truth.