Graduation date: 1982

Thesis (Ph. D.)--University of Chicago, Dept. of Economics, March 1997. / Includes bibliographical references. Also available on the Internet.

This dissertation consists of four essays in economic theory. All of them fall under the umbrella of economics of information; we study various models of game-theoretic interaction between players who are communicating with others, and have (or are able to produce) information of some sort. There is a large emphasis on the interplay of information, incentives and beliefs. In the first chapter we study a model of communication and persuasion between a sender who is privately informed and has state independent preferences, and a receiver who has preferences that depend on the unknown state. In a model with two states of the world, over the interesting range of parameters, the equilibria can be pooling or separating, but a particular novel refinement forces the pooling to be on the most informative information structure in interesting cases. We also study two extensions - a model with more information structures as well as a model where the state of the world is non-dichotomous, and show that analogous results emerge. In the second chapter, which is coauthored with Joseph E. Stiglitz and Jungyoll Yun, we study the Rothschild-Stiglitz model of competitive insurance markets with endogenous information disclosure by both firms and consumers. We show that an equilibrium always exists, (even without the single crossing property), and characterize the unique equilibrium allocation. With two types of consumers the outcome is particularly simple, consisting of a pooling allocation which maximizes the well-being of the low risk individual (along the zero profit pooling line) plus a supplemental (undisclosed and nonexclusive) contract that brings the high risk individual to full insurance (at his own odds). We also show that this outcome is extremely robust and Pareto efficient. In the third chapter we study a game of strategic information design between a sender, who chooses state-dependent information structures, a mediator who can then garble the signals generated from these structures, and a receiver who takes an action after observing the signal generated by the first two players. Among the results is a novel (and complete, in a special case) characterization of the set of posterior beliefs that are achievable given a fixed garbling. We characterize a simple sufficient condition for the unique equilibrium to be uninformative, and provide comparative statics with regard to the mediator’s preferences, the number of mediators, and different informational arrangements. In the fourth chapter we study a novel equilibrium refinement - belief-payoff monotonicity. We introduce a definition, argue that it is reasonable since it captures an attractive intuition, relate the refinement to others in the literature and study some of the properties.

This thesis includes one essay on incomplete information and two essays on the capital market implications of asymmetric information. The acquisition of information and its dissemination to all economic units are central activities in capital markets. Limits to information diffusion may exist when market participants have limited processing ability or when market structure causes information asymmetry to persist. Merton (1987) proposes a simple capital market equilibrium model with incomplete information, in which difference in a stock’s investor recognition affects its cost of capital. Myers and Majluf (1984) lay out the theoretical foundation for the role of asymmetric information in corporate finance and its capital market implications. The first essay tests and offers support to Merton’s (1987) theory. In the U.S. market, using the breadth of ownership among retail investors as a proxy for investor recognition, I show that a long-short portfolio based on the annual change of shareholder base earns a compounded annual abnormal return of 6.42% after controlling for the Fama-French three factors. These results are more pronounced among young, low visibility and high idiosyncratic volatility stocks. Moreover, I present evidence that the investor recognition effect can explain approximately 20% of the puzzling net equity issuance effect documented by Pontiff and Woodgate (2008). The second essay suggests a novel signaling mechanism in the framework of asymmetric information. When a firm’s convertible debt is issued, it is not only determined by the fundamentals of the firm such as past stock performance, but also related to whether this performance is realized during the tenure of current CEO who decides the issues. I define the performance that the current CEO achieves in the firm ever since the CEO comes to the helm as CEO-specific performance. Higher CEOspecific performance leads to (1) a higher probability of convertible issues, and (2) a less negative abnormal stock return in response to the convertible issue announcement, controlling for other firm characteristics. These evidences indicate that CEO-specific performance serves as a credible information signal to influence the adverse selection costs between the firm and outside investors in convertible bond financing. The third essay explores the possibility of asymmetric information in explaining the pronounced share issue anomaly in the cross-sectional variations of stock returns, as documented by Pontiff and Woodgate (2008). A lot of equity share issue and repurchase actions are actively determined by the decision of corporate stakeholders, such as employees at the stock options exercises. As these stakeholders hold a large amount of private information about the firm, it is in their optimal decisions to try to time the exercise of their share purchase activity, but outside investors are likely to fail to interpret the information revealed from these actions. I present strong evidence that a negative relation between share issues and stock returns is affected to a greater extent when the information asymmetry problem is more severe. / published_or_final_version / Business / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of California, Santa Cruz, 1994. / Typescript. Includes bibliographical references (leaves 253-259).

This dissertation studies communication in a variety of contexts and attempts to derive general comparative statics results and equilibrium characterizations. The main goal is to understand how usual comparative statics predictions extend to realistic but previously intractable frameworks. These range from examining communication when outcomes are lotteries, to disclosure games when the evidence structure can be arbitrarily complex. Chapter 1 studies verifiable disclosure games, that is, a sender communicating with a receiver using hard evidence in order to influence his action choice. The main goal is to understand how prior beliefs about the evidence environment affect which actions are chosen in equilibrium. More specifically, the goal is to understand which beliefs will be less preferred by the sender: I say that a prior belief is more skeptical than another if it induces less preferred equilibrium actions for the sender regardless of his type or the receiver's preferences. The main contribution is to show that this equilibrium order, which is difficult to check. is equivalent to when the sender is expected to have more evidence, a more straightforward order over the primitives. This equivalence has application to any disclosure game in which the sender can affect or choose the receiver that he faces. Examples include jury selection and dynamic disclosure. In addition, the methodology of the paper provides an explicit expression for equilibrium actions, and a novel comparative statics result. Chapter 2 studies when choice over lotteries is monotonic given any choice set. A central prediction of the signaling literature is monotone comparative statics (MCS) or that higher types choose higher outcomes. The driving behavioral assumption behind MCS is the single crossing property on preferences. However, this property is only sufficient when the outcome is non-random. More realistically, choices correspond to lotteries over outcomes: a student choosing her education level is not certain about her lifetime salary. Motivated by this observation we characterize preferences that admit an analogous single crossing property over lotteries. We show that this property is necessary and sufficient to maintain MCS in many signaling applications when noise is introduced after the choice has been made. Chapter 3 studies how a principal incentivizes costly information acquisition from a disinterested agent through monetary transfers. The main focus is the moral hazard that arises when the principal can observe the results of the investigation but not the entire research process. More specifically, we assume that the principal can contract on the realized posterior belief but not on the posterior beliefs that could have been realized or on their probability. We find that, unlike in standard moral hazard problems, under either limited liability or risk aversion the principal implements his first best experiment at first best cost. However, under risk aversion and limited liability the principal suffers efficiency loss. More specifically, if the principal plans to implement an asymmetric experiment, one which seeks certainty with low probability and is uninformative otherwise, the second best experiment will be distorted toward less asymmetric experiments and provide the agent with a positive rent.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 56-59).

Thesis (Ph. D.)--University of Chicago, Department of Economics, August 2000. / Includes bibliographical references. Also available on the Internet.

No description available.

This dissertation studies information acquisition when the choice of information is fully flexible. Throughout the dissertation, I consider a theoretical framework where a decision maker (DM) acquires costly information (signal process) about the payoffs of different alternatives before making a choice. In Chapter 1, I solve a general model where the DM pays a cost that depends on the rate of uncertainty reduction and discounts delayed payoffs. The main finding is that the optimal signal process resembles a Poisson signal --- the signal arrives occasionally according to a Poisson process, and it drives the inferred posterior belief to jump discretely. The optimal signal is chosen to confirm the DM's prior belief of the most promising state. Once seeing the signal, the decision maker is discretely surer about the state and stops learning immediately. When the signal is otherwise absent, the decision maker becomes gradually less sure about the state, and continues learning by seeking more precise but less frequently arriving signals. In Chapter 2, I study the sequential implementation of a target information structure. I characterize the set of decision time distributions induced by all signal processes that satisfy a per-period learning capacity constraint on the rate of uncertainty reduction. I find that all decision time distributions have the same mean, and the maximal and minimal elements by mean-preserving spread order are exponential distribution and deterministic distribution. The result implies that when the time preference is risk loving (e.g. standard or hyperbolic discounting), Poisson signal is optimal since it induces the riskiest exponential decision time distribution. When time preference is risk neutral (e.g. constant delay cost), all signal processes are equally optimal. In Chapter 3, I relax the assumption on information cost by assuming that the measure of signal informativeness is an indirect measure from sequential minimization. I first show that an indirect information measure is supported by sequential minimization iff it satisfies: 1) monotonicity in Blackwell order, 2) sub-additivity in compound experiments and 3) linearity in mixing with no information. Then I study a dynamic information acquisition problem where the cost of information depends on an indirect information measure and the delay cost is fixed (the DM is time-risk neutral). The optimal strategy is to acquire Poisson type signals. The result implies that when the cost of information is measured by an indirect measure, Poisson signals are intrinsically cheaper than other signal processes. Chapter 4 introduces a set of useful technical results on constrained information design that is used to derive the main results in the first three chapters.