The quintessential crime of the information age is identity theft, the malicious use of personal identifying data. In this paper we model "identity" and its use in credit transactions. Various types of identity theft occur in equilibrium, including "new account fraud," "existing account fraud,"...

A controversial aspect of payment cards has been the “no-surcharge rule.” This rule, which is part of the contract between the card provider and a merchant, states that the merchant cannot charge a customer who pays by card more than a customer who pays by cash. In this paper we consider the...