The Value of a Reputation System

This paper explores the trade-off between the short-term benefits of false quality advertisements against the longer term costs of reputation damage. A directed search model is constructed in which submarkets are created by the advertisements and reputations of sellers. A reputation system links misleading advertisements in the present period to a lower reputation in the next period. We show that a reputation system always increases the prices of high quality products and directs search more accurately towards the sellers with such products. We also show that buyers are hurt by a reputation system if the market is thin -- has few sellers -- because the equilibrium increase in prices is greater than the equilibrium increase in the quality of trade. Finally, we show that a reputation system which screens for honesty increases social welfare by making sellers more truthful. However, we also show that a reputation for honesty is not always highly valued and that an alternative reputation system which screens for type can be more effective.