Strategic Implications of Uncertainty over One's Own Private Value in Auctions

A rational bidder in a private-value auction should be reluctant to incur the cost of perfectly estimating his value if it might not matter to the success of his bidding strategy. This can explain sniping---flurries of bids at the end of auctions---as the result of other bidders trying to avoid stimulating the victim into learning more about his value. The idea of value discovery also explains why a bidder might increase his bid ceiling in the course of an auction and why he would like to know the private values of other bidders.

A Vague Theory of Choice over Time

We propose a novel approach to modelling time preferences, based on a cognitive shortcoming of human decision makers: the perception of future events becomes increasingly `blurred' as the events are pushed further in time. Our model explains behavioural `anomalies' such as preference reversal and cyclical choice.

Choice under Limited Uncertainty

This paper considers the problem of an agent's choice under uncertainty in a new framework. The agent does not know the true probability distribution over the state space but is objectively informed that it belongs to a specified set of probabilities. Maintaining the hypothesis that this agent is a subjective expected utility maximizer, we address the question of how the objective information influences her subjective prior.Three plausible rules are proposed. The first, named state independence, states that the subjective probability should not depend on how the uncertain states are `labeled'. Location-consistency, the second property, assumes that `similar' objective sets of probabilities result in `similar' subjective priors. The third rule is an `update-consistency' rule. Suppose the agent selects some probability p. She is then told that the likelihood assigned by p to some event A is in fact correct; then this should not cause her to revise her choice of p.Another property, alternative to update-consistency, is also proposed. When an agent forms her subjective prior assigning subjective probabilities to events in some ordered sequence, this property requires that the resulting prior be independent of that order. This last property, named order independence, is shown to be equivalent to update-consistency.A class of sets of probabilities is found on which state independence, location-consistency and update consistency (order independence) uniquely determine a selection rule. Some intuition is given regarding why these properties work in this collection of problems.

The Principal-Agent Matching Market

We propose an agency model based on competitive markets in order to analyse an economy with several homogeneous principals and heterogeneous agents. We model the principal-agent economy as a two-sided matching game and characterise the set of stable outcomes (equilibria) of this market. In this regard we generalise the assignment game of Shapley and Shubik (1972). Unlike in the standard principal-agent theory, equilibrium payoffs of all the individuals are endogenous, equilibrium contracts are Pareto optimal, and the incremental surplus generated in a principal-agent relationship accrues to the tenant. We design a simple non-cooperative game which implements the set of stable outcomes in subgame perfect equilibrium. We also suggest policy measures in relation to efficiency and income distribution.

Status Concerns and Occupational Choice Under Uncertainty

This paper examines the consequences of status preferences on entrepreneurial risk-taking in a general equilibrium model of occupational choice. We distinguish between two frames of reference. In the first, status is derived from class-membership, the economic indicator of which is the expected relative income of the person's occupation. In the second, status is tied to individual income relative to the mean. We find that the effect of status needs depends on whether or not the status variable itself is subject to risk. While social status increases entrepreneurial risk-taking in the first case, the effect is ambiguous in the second and crucially depends on how status preferences alter the effective degree of risk aversion. The results carry over to the distributional consequences, where status preferences have an equalizing effect only if certain conditions are met.

Limited Observation in Mutual Consent Networks

This paper studies mutual consent social networks in which individuals imperfectly monitor others' network ties and have incomplete information about the benefits of network participation. I introduce the Conjectural Pairwise Stability concept, which generalizes Jackson and Wolinsky's (1996) Pairwise Stability concept to allow for limited observation, and apply it to a specific mutual consent network formation game. While limited observation generally leads to the existence of less efficient stable networks, I find that it can also lead to the existence of efficient stable networks. Moreover, stability restrictions considered in previous work lose their refining power as observation becomes more limited.

Party Competition under Private and Public Financing: A Comparison of Institutions

We propose a theory of party competition (two parties, single-issue) where citizens acquire party membership by contributing money to a party, and where a member’s influence on the policy taken by her party is proportional to her campaign contribution. The polity consists of informed and uninformed voters: only informed voters join parties, and the party campaign chest, the sum of its received contributions, is used to reach uninformed voters through advertising. A party is a cooperative organization of its members. Parties compete with each other strategically with respect to policy choice and advertising. We propose a definition of political equilibrium, in which party membership, citizen contributions, and parties’ policies are simultaneously determined, for each of four financing institutions, running the gamut between a purely private, unconstrained system, to a public system in which all citizens have equal financial input. Equilibria under these institutions are computed by simulation for an example. The representation and welfare properties of these four institutions are compared from these simulations.

Evolutionary Dynamics and Long-Run Selection

We study the emergence and nature of long-run behavior of continuous state space dynamics that are subjected to random shocks. It is shown that the fine details of the underlying deterministic dynamics may be crucial in determining the evolution of the system. In particular, a risk dominated strategy can emerge in an evolutionary game subject to symmetric decaying perturbations.