Rethinking the Micro-Foundation of Opinion Dynamics
数学专题报告
报告题目(Title)：Rethinking the Micro-Foundation of Opinion Dynamics
报告人(Speaker)： 梅文俊（北京大学）
地点(Place)：后主楼 1223
时间(Time)：2022 年 4 月6日（周三） 10:00--11:00
邀请人(Inviter)：张博宇
报告摘要
The key to obtaining a mechanistic and reliable understanding of complex public opinion formation processes is to identify the main mechanism governing interpersonal influence. Researchers have long been exploring simple yet predictive mathematical models of opinion dynamics. Although most models are based on the assumption that individuals update their opinions by averaging others’ opinions, researchers might need to rethink this universally-adopted micro-foundation. The deceivingly simple weighted-averaging mechanism features a non-negligible unrealistic implication, which brings unnecessary difficulties in seeking a proper balance between model complexity and predictive power. In this paper, we fundamentally resolve this problem by proposing the weighted-median mechanism as a new micro-foundation of opinion dynamics. Such an inconspicuous change from averaging to median leads to rich consequences. The weighted-median mechanism, derived from the cognitive dissonance theory in psychology, is well supported by online experiment data. It also broadens the applicability of opinion dynamics models to multiple-choice issues with ordered discrete options, e.g., political elections. Moreover, comparative studies show that the weighted-median mechanism predicts various real-world patterns of opinion evolution while some widely-studied averaging-based models fail to, including how group structure affects the likelihood of reaching consensus and how extreme opinions are located in social networks.
主讲人简介
Wenjun Mei is an assistant professor at the Department of Mechanics and Engineering Science, Peking University. Before joining Peking University, he was a postdoctoral researcher in the Automatic Control Laboratory at ETH, Zurich. He received the Bachelor of Science degree in Theoretical and Applied Mechanics from Peking University and the Ph.D. degree in Mechanical Engineering from University of California, Santa Barbara. He is on the editorial board of the Journal of Mathematical Sociology and has been a technical reviewer for journals including Nature Communications, IEEE TAC and Automatica. Wenjun Mei’s research mainly focuses on the modeling, analysis, and control of network dynamical systems, including but not limited to social and economic networks, network games, group decision making, and evolutionary games.
