We consider an exchange economy in which agents possess private information at the time of engaging in state contingent contracts. While communication of private information is permitted, the true information state is not verifiable. The enforcement of contracts is, therefore, limited by incentive compatibility constraints. We formalize a notion of the core for such an economy. Our analysis can...

We study deterministic voting mechanisms by considering an ordinal notion of Bayesian incentive compatibility (OBIC). If the beliefs of agents are independent and generic, we show that a mechanism is OBIC and satisfies an additional condition called elementary monotonicity if and only if it is a dominant strategy incentive compatible mechanism. Our result works in a large class of preference do...

We consider an adverse selection environment, where an agent is able to understate his productivity, but not allowed to overstate it. We characterize the principal’s optimization problem. The solution to this problem is generally different than the solution to the standard problem, where no restriction is made on the statements that the agent can make. We identify a sufficient condition under w...

An allocation rule is called Bayes-Nash incentive compatible, if there exists a payment rule, such that truthful reports of agents’ types form a Bayes-Nash equilibrium in the direct revelation mechanism consisting of the allocation rule and the payment rule. This paper provides a characterization of Bayes-Nash incentive compatible allocation rules in social choice settings where agents have mul...

We study the manipulability of stable matching mechanisms. To quantify incentives to manipulate stable mechanisms, we consider markets with random cardinal utilities, which induce ordinal preferences over match partners. We show that most agents in large matching markets are close to being indifferent overall stable matchings. In oneto-one matching, the utility gain by manipulating a stable mec...

Consider a buyer participating in a repeated auction, such as those prevalent in display advertising. How would she test whether the auction is incentive compatible? To bid effectively, she is interested in whether the auction is single-shot incentive compatible—a pure second-price auction, with fixed reserve price—and also dynamically incentive compatible—her bids are not used to set future re...

We study implementability in dominant strategies of social choice functions when types are multi-dimensional, sets of outcomes are arbitrary, valuations for outcomes are convex functions in the type, and utilities over outcomes and payments are quasi-linear. Archer and Kleinberg [1] have proven that in case of convex sets of types and linear valuation functions monotonicity in combination with ...

Reasoning about agent preferences on a set of alternatives, and the aggregation of such preferences into some social ranking is a fundamental issue in reasoning about multi-agent systems. When the set of agents and the set of alternatives coincide, we get the ranking systems setting. A famous type of ranking systems are page ranking systems in the context of search engines. Such ranking systems...

Reputation systems, which rank agents based on feedback from past interactions, play a crucial role in aggregating and sharing trust information online. Reputation systems are used to find authoritative web sites and ensure socially beneficial behavior on auction sites. The main problem faced by reputation system researchers is a lack of good metrics for comparison and evaluation. This thesis d...

Proving the incentive compatibility of an auction mechanism is always a hard but essential work in auction mechanism design. In this paper we discuss the strategy proofness of a multi-attribute auction mechanism using three different approaches: the analysis of the mechanism properties, a mathematical analysis to determine if agents can take advantage of dishonest strategies and the use of simu...