金融与财务学系列讲座之327期

Topic: When Competition Backfires: Broker Learning and Commission Fees

Time：14:00-15:30, Tuesday, Nov 11, 2025

Location: Room 603, Starr Building（史带楼603室）

Speaker: Xuewei Yang

Nanjing University

Abstract: This paper examines how learning and competition shape brokerage commission fees in a plain-vanilla Chinese setting. We document three facts: substantial price dispersion across investors, higher fees for naïve investors, and widening dispersion over time. To explain these patterns, we develop a dynamic model in which brokers compete for naïve and sophisticated clients while learning types through repeated interactions. The model shows that an incumbent's information advantage can sustain persistent market power—even over sophisticated investors—and that additional broker entry can backfire by raising markups on naïve investors and widening dispersion. Exploiting branch-level variation in rival presence, we provide causal evidence consistent with these predictions. Quantitatively, although the average number of brokers per city more than doubled over the sample, intensified competition slightly offset—rather than accelerated—the secular decline in fees.

Bio: 杨学伟，南京大学工程管理学院教授，博士生导师，南京大学社会科学处副处长，南京大学金融工程研究中心副主任，国家级一流本科课程负责人。主要从事金融衍生品、行为金融、应用随机模型研究，主持国家自然科学基金国际(合作)研究重点项目和优秀青年科学基金项目等国家级科研项目5项，其中面上项目结题获评“特优”；研究成果发表于Journal of Finance、Journal of Financial Economics、Review of Financial Studies、INFORMS Journal on Computing和Mathematical Finance等期刊，部分成果荣获陕西省自然科学奖和江苏省哲学社会科学优秀成果奖。兼任江苏省金融青联副主席，中国系统工程学会金融系统工程专业委员会副主任委员，管理科学与工程学会金融计量与风险管理分会副主任委员，全国工业统计学教学研究会金融科技与大数据技术分会副理事长。