Journal of Socio-Economics 32 (2003) 661–673 Herd behavior and the quality of opinions Shinji Teraji Department of Economics, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8514, Japan Accepted 14 October 2003 Abstract This paper analyzes a decentralized decision model by adding some inertia in the social leaning process. Before making a decision, an agent can observe the group opinion in a society. Social learning can result in a variety of equilibrium behavioral patterns. For insufficient ranges of quality (precision) of opinions, the chosen stationary state is unique and globally accessible, in which all agents adopt the superior action. Sufficient quality of opinions gives rise to multiple stationary states. One of them will be characterized by inefficient herding. The confidence in the majority opinion then has serious welfare consequences. © 2003 Elsevier Inc. All rights reserved. JEL classification: D83 Keywords: Herd behavior; Social learning; Opinions; Equilibrium selection 1. Introduction Missing information is ubiquitous in our society. Product alternatives at the store, in catalogs, and on the Internet are seldom fully described, and detailed specifications are often hidden in manuals that are not easily accessible. In fact, which product a person decides to buy will depend on the experience of other purchasers. Learning from others is a central feature of most cognitive and choice activities, through which a group of interacting agents deals with environmental uncertainty. The effect of observing the consumption of others is described as the socialization effect. The pieces of information are processed by agents to update their assessments. Here people may change their preferences as a result of E-mail address:
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