Perfect and General Virtual Implementation For Perfectly Informed Players

We show that, when the players are perfectly informed about each other, essentially all social-choice functions can be rationally robustly implemented via an extensive-form public-action mechanism that (1) is perfectly robust against collusion, (2) requires only a linear number of computation steps and communication bits, and (3) preserves the privacy of the players' types to a very high extent

Robustly Leveraging Collusion in Combinatorial Auctions

Because of its devastating effects in auctions and other mechanisms, collusion is prohibited and legally prosecuted. Yet, colluders have always existed, and may continue to exist. We thus raise the following question for mechanism design: What desiderata are achievable, and by what type of mechanisms, when any set of players who wish to collude are free to do so without any restrictions on the way in which they cooperate and coordinate their actions? In response to this question we put forward and exemplify the notion of a collusion-leveraging mechanism. In essence, this is a mechanism aligning its desiderata with the incentives of all its players, including colluders, to a significant and mutually beneficial extent. Of course such mechanisms may exist only for suitable desiderata. In unrestricted combinatorial auctions, where classical mechanisms essentially guarantee 0 social welfare and 0 revenue in the presence of just two colluders, we prove that it is possible for collusion-leveraging mechanisms to guarantee that the sum of social welfare and revenue is always high, even when all players are collusive. To guarantee better performance, collusion-leveraging mechanisms in essence “welcome" collusive players, rather than pretending they do not exist, raising a host of new questions at the intersection of cooperative and noncooperative game theory

Mechanism design with partially-specified participation games

This paper considers the implementation of an economic outcome under complete information when the strategic and informational details of the participation game are partially-specified. This means that full participation is required to be a subgame-perfect equilibrium for a large variety of extensive modifications of the simultaneous-move participation game in the same vein as Kalai [Large Robust Games, Econometrica 72 (2004) 1631-1665].mechanism design ; robust implementation ; strong Nash equilibrium ; partial subgame perfection ; collusion on participation

Information in Mechanism Design

We survey the recent literature on the role of information for mechanism design. We specifically consider the role of endogeneity of and robustness to private information in mechanism design. We view information acquisition of and robustness to private information as two distinct but related aspects of information management important in many design settings. We review the existing literature and point out directions for additional future work.Mechanism Design, Information Acquisition, Ex Post Equilibrium, Robust Mechanism Design, Interdependent Values, Information Management

Information in Mechanism Design

We survey the recent literature on the role of information in mechanism design. First, we discuss an emerging literature on the role of endogenous payoff and strategic information for the design and the efficiency of the mechanism. We specifically consider information management in the form of acquisition of new information or disclosure of existing information. Second, we argue that in the presence of endogenous information, the robustness of the mechanism to the type space and higher order beliefs becomes a natural desideratum. We discuss recent approaches to robust mechanism design and robust implementation.Mechanism Design, Information Acquisition, Ex Post Equilibrium, Robust Mechanism Design, Interdependent Values, Information Management

Fair Use and First Amendment: Without Fair Use, What Would You Freely Speak About?

The question this paper tries to answer is: Without fair use, what would you freely speak about? This paper will seek to demonstrate that the Copyright Clause’s Fair Use doctrine, and the First Amendment are cousins who help each other, rather than enemies sworn to destroy each other as some believe. First I will give a brief overview and history of each doctrine. Next I will speak about three areas where I believe fair use and the First Amendment cross paths extensively. These areas are: (1) school/education; (2) social media and news; and (3) sports images/broadcasting. Finally, I will demonstrate how fair use is as important if not more important than the First Amendment for these categories that I have listed

Markets for information : of inefficient firewalls and efficient monopolies

In this paper we build a formal model to study market environments where information is costly to acquire and is of use also to potential competitors. In such situations a market for information may form, where reports - of unverifiable quality - over the information acquired are sold. A complete characterization of the equilibria of the game is provided. We find that information is acquired when its costs are not too high and in that case it is also sold, though reports are typically noisy. Also, the market for information tends to be a monopoly, and there is typically inefficiency given by underinvestment in information acquisition. Regulatory interventions in the form of firewalls, limiting the access to the sale of information to third parties, uninterested in trading the underlying object, only make the inefficiency worse. On the other hand, efficiency can be attained with a monopolist selling differentiated information, provided entry is blocked. The above findings hold when information has a prevalent horizontal differentiation component. When that is not the case, and the vertical differentiation element is more important, firewalls can in fact be beneficial

Do Opponents' Experience Matter? Experimental Evidence from a Quantity Precommitment Game

This paper investigates why subjects in laboratory experiments on quantity precommitment games consistently choose capacities above the Cournot level - the subgame-perfect equilibrium. We argue that this puzzling regularity may be attributed to players' perceptions of their opponents' skill or level of rationality. In our experimental design, we use the level of experience (the number of periods played) as a proxy for the level of rationality and match subjects with different levels of experience. We first find evidence of capacity choices decreasing, and prices increasing, with the opponent's experience. Futhermore, we investigate the observed behavioural patterns by using the agent-form quantal response equilibrium model by McKelvey and Palfrey (1998). In particular, this framework takes into account any interaction between a player's own experience and that of his opponent. We show how the predictions of this theoretical framework fit well with the experimental data.Oligopoly; Quantity precommitment; Experience; Rationality

Private Information in Sequential Common-Value Auctions

We study an infinitely-repeated ?rst-price auction with common values. Initially, bid- ders receive independent private signals about the objects' value, which itself does not change over time. Learning occurs only through observation of the bids. Under one-sided incomplete information, this information is eventually revealed and the seller extracts es- sentially the entire rent (for large discount factors). Both players?payo¤s tend to zero as the discount factor tends to one. However, the uninformed bidder does relatively better than the informed bidder. We discuss the case of two-sided incomplete information, and argue that, under a Markovian re?nement, the outcome is pooling: information is revealed only insofar as it does not affect prices. Bidders submit a common, low bid in the tradition of collusion without conspiracy.repeated game with incomplete information; private information; ratchet effect; first-price auction; dynamic auctions