Book contents
- Frontmatter
- Contents
- Preface
- 1 Introduction
- PART ONE Social Learning
- 2 Bayesian Tools
- 3 Social Learning with a Common Memory
- 4 Cascades and Herds
- 5 Limited Memories
- 6 Delays
- 7 More Delays
- 8 Outcomes
- 9 Networks and Diffusion
- 10 Words
- PART TWO Coordination
- PART THREE Financial Herding
- References
- Author Index
- Subject Index
10 - Words
Published online by Cambridge University Press: 12 January 2010
- Frontmatter
- Contents
- Preface
- 1 Introduction
- PART ONE Social Learning
- 2 Bayesian Tools
- 3 Social Learning with a Common Memory
- 4 Cascades and Herds
- 5 Limited Memories
- 6 Delays
- 7 More Delays
- 8 Outcomes
- 9 Networks and Diffusion
- 10 Words
- PART TWO Coordination
- PART THREE Financial Herding
- References
- Author Index
- Subject Index
Summary
If we all think alike, it means we do not think anymore.
Trust but verify.
In this chapter, the actions of agents (experts) are words (messages). The payoff depends on the message and some independent information of the receiver of the message. The condition for no herding and telling the truth is the same as in the BHW model of Chapter 4. In some cases, the payoff depends on a reputation for being informed or for being nonmanipulative. An expanded set of messages may not improve the transmission of information (contrary to Chapter 4). If the expert has information on the independent information of the receiver, the receiver should try to increase his information. The order in which experts should speak in a panel (trial jury) is analyzed: the antiseniority rule does not seem to be superior to other rules.
Communication with words is the subject of a vast literature. This chapter will be selective and focus on the relations between models of communication through words (models of “cheap talk”) and the issues of social learning that are addressed in other parts of this book. For example, herding may arise in financial markets because of the observation of others' actions or because of the behavior of financial advisors who are influenced by others' predictions. We will see that herding on actions and herding on words occur under similar conditions.
In the generic setting, an agent is an expert with private information on the state of nature, and his action takes the form of a message that is sent to a receiver. How can he transmit his information credibly by mere words?
- Type
- Chapter
- Information
- Rational HerdsEconomic Models of Social Learning, pp. 211 - 234Publisher: Cambridge University PressPrint publication year: 2003