Essays on mechanism and market design [electronic resource]

The focus of this dissertation is the role of information in the determination of market outcomes. The first essay provides a novel framework for studying large market mechanisms with an application to the information aggregation properties of uniform price auctions. The second essay analyzes a model of mood and associative memory and shows that this bias could explain anomalous results in the behavioral finance and organizational behavior literatures. The third and final essay analyzes ambiguity aversion and how it affects outcomes in general mechanisms. The first essay, "Mean Field Approximation of Large Games, " provides a general framework for approximating the equilibria of games with many participants using analytically tractable nonatomic limit games. We prove that if the game is continuous, then the set of equilibria is upper hemicontinuous in the number of agents. This implies that we can use equilibrium strategies of the limit game as an approximation of the equilibrium actions of the agents in the large finite game. We argue that this continuity property implies that generic large, continuous markets are almost competitive in the limit. We use our framework to analyze multi-unit demand uniform price auctions with both a common value component and bidders who value successive units as complements. We show that these auctions fully reveal the state of the world asymptotically and result in ex post efficient allocations with arbitrarily high probability in the asymptotic limit. As a second application, we provide a framework for approximating large stochastic games using dynamic competitive equilibria with applications to macroeconomics, industrial organization, engineering and computer science. The second essay, "Mood and Associative Memory, " examines the biases in memory caused by an agent's affective state. Within the psychology literature, it is a well established fact that decision makers in a positive emotional state are optimistic about the odds of positive random events and agents in a negative emotional state are pessimistic. By building a mathematical model firmly grounded on psychological primitives, we develop a behavioral decision theory framework that can be utilized in a wide range of microeconomic models. We apply our model to study employee morale and clarify a severely conflicted literature on morale within the Organizational Behavior literature. We also show that biases in memory are a potential explanation for a wide range of asset pricing anomalies such as excess volatility, short run underreaction and long run overreaction to news, and the influence of non-fundamental events. Our model provides a tool for policy makers to analyze the effects of biases in memory on the response of agents to firms, markets, and government policies and can be used to identify situations in which either public or private intervention may be required to ameliorate the effects of the agents' errors in judgment. The third and final essay, "Ambiguous Beliefs and Mechanism Design, " explores the effects of ambiguity aversion, also known as Knightian Uncertainty, on mechanism design theory. Knightian uncertainty refers to risk within the economy that is not characterized by a stochastic process commonly known to the agents. Compelling psychological data, such as the classical Ellsberg Paradox, have shown that agents reveal a strong aversion to Knightian Uncertainty above and beyond the risk aversion considered in neoclassical microeconomic theory. Policy makers ought to be especially concerned about the effects of ambiguity aversion, neglected in traditional studies of mechanism and market design, in situations where the agents are unfamiliar with the mechanism and the economic environment the mechanism creates. We unify the Multiple Prior Expected Utility (MEU) model of ambiguity aversion with the tools of contract theory to provide a general framework to analyze the effects of ambiguity aversion in market settings and use these tools to assess the effect of ambiguity aversion on auctions and bargaining problems. We show that the first and second price auction cannot be ranked when the agents are ambiguity averse, derive the optimal auction format, and study the effects of ambiguity on auction entry. We also prove that ambiguity aversion can be efficiency enhancing in ex ante budget balanced mechanisms and revenue enhancing in ex post efficient bargaining mechanisms.

Keywords: Economics
Advisor: Segal Ilya primary advisor. Thesis advisor
Bernheim B. Douglas advisor. Thesis advisor
Milgrom Paul R. (Paul Robert)