[This article develops a model of competitive bidding with a resale market. The primary market is modeled as a common-value auction, in which bidders participate for the purpose of resale. After the auction the winning bidders sell the objects in a secondary market, and the buyers in the secondary market receive information about the bids submitted in the auction. The effect of this information linkage between the primary auction and the secondary market on bidding behavior in the primary auction is examined. The auctioneer's expected revenues from organizing the primary market as a discriminatory auction versus a uniform-price auction are compared, and sufficient conditions under which the uniform-price auction will yield higher expected revenues are obtained. An example of our model, with the primary market organized as a discriminatory auction, is the U.S. Treasury bill market.]

Multiplicity of sequential equilibria is a common problem in bargaining models with incomplete information in which the informed player makes an offer. Most of these equilibria are supported by optimistic conjectures by the uninformed player. This paper reexamines the bargaining model in Rubinstein (1953). Monotonicity restrictions are placed on off-the-equilibrium-path beliefs to exclude equilibria supported by optimistic conjectures. Sequential equilibria that survive these restrictions are characterized.

An informational cascade occurs when it is optimal for an individual, having observed the actions of those ahead of him, to follow the behavior of the preceding individual without regard to his own information. We argue that localized conformity of behavior and the fragility of mass behaviors can be explained by informational cascades.

An informational cascade occurs when it is optimal for an individual, having observed the actions of those ahead of him, to follow the behavior of the preceding individual without regard to his own information. We argue that localized conformity of behavior and the fragility of mass behaviors can be explained by informational cascades.

Social learning is the updating of beliefs based on observation of others. Such observation can lead to efficient aggregation of information, but also to inaccurate decisions, fragility of mass behaviors, and, in the case of information cascades, to complete blockage of learning. We review the theory of information cascades and social learning and discuss important themes, insights, and applications of this literature as it has developed over the last 30 years. We also highlight open questions and promising directions for further theoretical and empirical exploration.

We characterize dominant-strategy incentive compatibility with multidimensional types. A deterministic social choice function is dominant-strategy incentive compatible if and only if it is weakly monotone (W-Mon). The W-Mon requirement is the following: If changing one agent's type (while keeping the types of other agents fixed) changes the outcome under the social choice function, then the resulting difference in utilities of the new and original outcomes evaluated at the new type of this agent must be no less than this difference in utilities evaluated at the original type of this agent.