Title: An Axiomatic Approach to Collective Decision-Making through Abstract Argumentation: Static and Dynamic Perspectives

Speaker: Weiwei Chen (Department of Philosophy, Sun Yat-sen University)

Time: 2024/03/19 15:10-18:00

Location: Room 313, Teaching Building No.2 (第二教学楼), Peking University

Abstract:

　　In this talk, I present an axiomatic approach to collective decision-making based on abstract argumentation. I begin with an introduction of abstract argumentation frameworks, followed by the axiomatic method in social choice theory and we pay special attention to Arrow's Impossibility Theorem and May's Theorem on the characterization of the majority rule. Then, I introduce an axiomatic study of the preservation of semantic properties of Dung's argumentation frameworks during the aggregation of attack-relations. I also introduce a study on how to relax preservation requirements or axioms of aggregation rules to make preservation possible. 

　　The first part of the talk examines aggregation processes in static terms, focusing on preserving semantic properties at a given time. In contrast, the second part of the talk investigates whether decisions remain rational when the preservation process is dynamic, meaning that it can incorporate new information. To address the dynamic nature of collective argumentation, we introduce the revision and contraction operators. These operators reflect the idea that when an individual or a group learns something new by accepting or rejecting an argument, they have to update their collective decision accordingly. Our study examines whether the order of revising individual opinions and aggregating them affects the final outcome, i.e., whether aggregation and revision commute.

Bio: 陈伟伟，中山大学哲学系及逻辑与认知研究所副教授，专注于形式论证（formal argumentation）和社会选择理论（social choice theory）。他的研究位于论证学、逻辑学、决策论交汇处，着重探讨群体决策问题。