S形需求曲线的动态起源——消费者社会相互作用下时尚商品的群体模型  

Dynamic Origin of the S-shape Demand Curve:A Population Model of Fashion Goods with Social Interaction among Consumers

作　　者：唐毅南[1] 陈平[2,3] 

机构地区：[1]复旦大学经济学院,上海200433 [2]北京大学国家发展研究院,北京100871 [3]复旦大学新政治经济学中心,上海200433

出　　处：《经济学（季刊）》2009年第2期1013-1028,共16页China Economic Quarterly

基　　金：国家社会科学基金会07BJL004项目的资助

摘　　要：时尚品消费是社会心理的典型现象，其需求变化的特点是跃变而非渐变。本文用人际相互作用下的“社会人”理性构造动态优化模型，来理解S形需求曲线的起源（Becker 1991）。时尚市场的特点是开放型的“进入或退出”机制。消费者心态的转变概率取决于社会风潮的吸引和过度拥挤的厌恶之间的竞争制衡。由此得出的S形曲线的不连续性导致需求的跃变。当社会相互影响强度变弱时，S形需求曲线中不稳定的正斜率部分会退化消失，成为近于单调向下的直线。Sudden changes in demand for fashion goods are a typical phenomenon in social psychology. Fashion behavior can be characterized as an ＂in-or-out＂ open market. A dynamic optimization model is introduced for modeling social rationality where social interactions among population members would change people＇s attitudes toward fashion goods. Consumer＇s transition probability depends on competition between neighbor attraction and ovet-crowding. The resulted S-shape demand curve （Becker, 1991） is discontinuous at the positive-sloped part. When the intensity of social influence is weak, the S-shape demand curve will be degenerated into a negative-sloped normal demand curve.

关 键 词：S形需求曲线 时尚品群体需求 “社会人”理性 

分 类 号：F014.5[经济管理—政治经济学] F014.32