Results 1  10
of
29
Congestion Games with Malicious Players
, 2008
"... We study the equilibria of nonatomic congestion games in which there are two types of players: rational players, who seek to minimize their own delay, and malicious players, who seek to maximize the average delay experienced by the rational players. We study the existence of pure and mixed Nash equ ..."
Abstract

Cited by 45 (0 self)
 Add to MetaCart
We study the equilibria of nonatomic congestion games in which there are two types of players: rational players, who seek to minimize their own delay, and malicious players, who seek to maximize the average delay experienced by the rational players. We study the existence of pure and mixed Nash equilibria for these games, and we seek to quantify the impact of the malicious players on the equilibrium. One counterintuitive phenomenon which we demonstrate is the “windfall of malice”: paradoxically, when a myopically malicious player gains control of a fraction of the flow, the new equilibrium may be more favorable for the remaining rational players than the previous equilibrium.
Altruism, selfishness, and spite in traffic routing
 In Proc. 9th Conf. Electronic Commerce (EC
, 2008
"... In this paper, we study the price of anarchy of traffic routing, under the assumption that users are partially altruistic or spiteful. We model such behavior by positing that the “cost ” perceived by a user is a linear combination of the actual latency of the route chosen (selfish component), and th ..."
Abstract

Cited by 24 (4 self)
 Add to MetaCart
(Show Context)
In this paper, we study the price of anarchy of traffic routing, under the assumption that users are partially altruistic or spiteful. We model such behavior by positing that the “cost ” perceived by a user is a linear combination of the actual latency of the route chosen (selfish component), and the increase in latency the user causes for others (altruistic component). We show that if all users have a coefficient of at least β> 0 for the altruistic component, then the price of anarchy is bounded by 1/β, for all network topologies, arbitrary commodities, and arbitrary semiconvex latency functions. We extend this result to give more precise bounds on the price of anarchy for specific classes of latency functions, even for β < 0 modeling spiteful behavior. In particular, we show that if all latency functions are linear, the price of anarchy is bounded by 4/(3 + 2β − β 2). We next study nonuniform altruism distributions, where different users may have different coefficients β. We prove that all such games, even with infinitely many types of players, have a Nash Equilibrium. We show that if the average of the coefficients for the altruistic components of all users is ¯ β, then the price of anarchy is bounded by 1 / ¯ β, for single commodity parallel link networks, and arbitrary convex latency functions. In particular, this result generalizes, albeit nonconstructively, the Stackelberg routing results of Roughgarden and of Swamy. More generally, we bound the price of anarchy based on the class of allowable latency functions, and as a corollary obtain tighter bounds for Stackelberg routing than a recent result of Swamy.
The Price of Malice in Linear Congestion Games
, 2008
"... We study the price of malice in linear congestion games using the technique of noregret analysis in the presence of Byzantine players. Our assumptions about the behavior both of rational players, and of malicious players are strictly weaker than have been previously used to study the price of malic ..."
Abstract

Cited by 18 (2 self)
 Add to MetaCart
We study the price of malice in linear congestion games using the technique of noregret analysis in the presence of Byzantine players. Our assumptions about the behavior both of rational players, and of malicious players are strictly weaker than have been previously used to study the price of malice. Rather than assuming that rational players route their flow according to a Nash equilibrium, we assume only that the play so as to have no regret. Rather than assuming that malicious players myopically seek to maximize the social cost of the game, we study Byzantine players about whom we make no assumptions, who may be seeking to optimize any utility function, and who may engage in an arbitrary degree of counterspeculation. Because our assumptions are strictly weaker than in previous work, the bounds we prove on two measures of the price of malice hold also for the quantities studied by Babaioff et al. [2] and Moscibroda et al. [17] We prove tight bounds both for the special case of parallel link routing games, and for general congestion games.
The robust price of anarchy of altruistic games
 In Proc. 7th Workshop on Internet and Network Economics (WINE
, 2011
"... We study the inefficiency of equilibria for several classes of games when players are (partially) altruistic. We model altruistic behavior by assuming that player i’s perceived cost is a convex combination of 1−αi times his direct cost and αi times the social cost. Tuning the parameters αi allows sm ..."
Abstract

Cited by 14 (3 self)
 Add to MetaCart
(Show Context)
We study the inefficiency of equilibria for several classes of games when players are (partially) altruistic. We model altruistic behavior by assuming that player i’s perceived cost is a convex combination of 1−αi times his direct cost and αi times the social cost. Tuning the parameters αi allows smooth interpolation between purely selfish and purely altruistic behavior. Within this framework, we study altruistic extensions of costsharing games, utility games, and linear congestion games. Our main contribution is an adaptation of Roughgarden’s smoothness notion to altruistic extensions of games. We show that this extension captures the essential properties to determine the robust price of anarchy of these games, and use it to derive mostly tight bounds. For congestion games and costsharing games, the worstcase robust price of anarchy increases with increasing altruism, while for utility games, it remains constant and is not affected by altruism. However, the increase in the price of anarchy is not a universal phenomenon: for symmetric singleton linear congestion games, the pure price of anarchy decreases both under increasing uniform altruism and as the fraction of entirely altruistic individuals increases.
Influence Diffusion Dynamics and Influence Maximization in Social Networks with Friend and Foe Relationships
, 2013
"... Influence diffusion and influence maximization in largescale online social networks (OSNs) have been extensively studied because of their impacts on enabling effective online viral marketing. Existing studies focus on social networks with only friendship relations, whereas the foe or enemy relation ..."
Abstract

Cited by 12 (2 self)
 Add to MetaCart
(Show Context)
Influence diffusion and influence maximization in largescale online social networks (OSNs) have been extensively studied because of their impacts on enabling effective online viral marketing. Existing studies focus on social networks with only friendship relations, whereas the foe or enemy relations that commonly exist in many OSNs, e.g., Epinions and Slashdot, are completely ignored. In this paper, we make the first attempt to investigate the influence diffusion and influence maximization in OSNs with both friend and foe relations, which are modeled using positive and negative edges on signed networks. In particular, we extend the classic voter model to signed networks and analyze the dynamics of influence diffusion of two opposite opinions. We first provide systematic characterization of both shortterm and longterm dynamics of influence diffusion in this model, and illustrate that the steady state behaviors of the dynamics depend on three types of graph structures, which we refer to as balanced graphs, antibalanced graphs, and strictly unbalanced graphs. We then apply our results to solve the influence maximization problem and develop efficient algorithms to select initial seeds of one opinion that maximize either its shortterm influence coverage or longterm steady state influence coverage. Extensive simulation results on both synthetic and realworld networks, such as Epinions and Slashdot, confirm our theoretical analysis on influence diffusion dynamics, and demonstrate that our influence maximization algorithms perform consistently better than other heuristic algorithms.
On strictly competitive multiplayer games
 In Proc. 21st Conf. Artificial Intelligence (AAAI
, 2006
"... We embark on an initial study of a new class of strategic (normalform) games, socalled ranking games, in which the payoff to each agent solely depends on his position in a ranking of the agents induced by their actions. This definition is motivated by the observation that in many strategic situati ..."
Abstract

Cited by 11 (2 self)
 Add to MetaCart
(Show Context)
We embark on an initial study of a new class of strategic (normalform) games, socalled ranking games, in which the payoff to each agent solely depends on his position in a ranking of the agents induced by their actions. This definition is motivated by the observation that in many strategic situations such as parlor games, competitive economic scenarios, and some social choice settings, players are merely interested in performing optimal relative to their opponents rather than in absolute measures. A simple but important subclass of ranking games are singlewinner games where in any outcome one agent wins and all others lose. We investigate the computational complexity of a variety of common gametheoretic solution concepts in ranking games and deliver hardness results for iterated weak dominance and mixed Nash equilibria when there are more than two players and pure Nash equilibria when the number of players is unbounded. This dashes hope that multiplayer ranking games can be solved efficiently, despite the structural restrictions of these games.
National Laboratory for Applied Network Research. Raw routing table information. http://moat.nlanr.net/Routing/rawdata
 In The Twenty Third Conference on Uncertainty in Artificial Intelligence
, 2007
"... We present a functional framework for automated Bayesian and robust mechanism design based on a twostage game model of strategic interaction between the designer and the mechanism participants, and apply it to several classes of twoplayer infinite games of incomplete information. At the core of ou ..."
Abstract

Cited by 7 (1 self)
 Add to MetaCart
(Show Context)
We present a functional framework for automated Bayesian and robust mechanism design based on a twostage game model of strategic interaction between the designer and the mechanism participants, and apply it to several classes of twoplayer infinite games of incomplete information. At the core of our framework is a blackbox optimization algorithm which guides the selection process of candidate mechanisms. Our approach yields optimal or nearly optimal mechanisms in several application domains using various objective functions. By comparing our results with known optimal mechanisms, and in some cases improving on the best known mechanisms, we show that ours is a promising approach to parametric design of indirect mechanisms. 1
Generating BayesNash equilibria to design autonomous trading agents
 In Proc. of the Twentieth International Joint Conference on Artificial Intelligence
, 2007
"... This paper presents a methodology for designing trading agents for complex games. We compute, for the first time, BayesNash equilibria for firstprice singleunit auctions and m thprice multiunit auctions, when the auction has a set of possible closing times, one of which is chosen randomly for th ..."
Abstract

Cited by 6 (6 self)
 Add to MetaCart
This paper presents a methodology for designing trading agents for complex games. We compute, for the first time, BayesNash equilibria for firstprice singleunit auctions and m thprice multiunit auctions, when the auction has a set of possible closing times, one of which is chosen randomly for the auction to end at. To evaluate this approach we used our analysis to generate strategies for the International Trading Agent Competition. One of these was evaluated as the best overall and was subsequently used very successfully by our agent WhiteBear in the 2005 competition. 1
Approaching utopia: strong truthfulness and externalityresistant mechanisms
 In Proceedings of the 4th conference on Innovations in Theoretical Computer Science
, 2013
"... ar ..."
Assessing the assumptions underlying mechanism design for the Internet
 In Proc. Workshop on the Economics of Networked Systems (NetEcon06), URL: http://www.cs. duke.edu/nicl/netecon06/papers/ne06assessing.pdf
, 2006
"... The networking research community increasingly seeks to leverage mechanism design to create incentive mechanisms that align the interests of selfish agents with the interests of a principal designer. To apply mechanism design, a principal designer must adopt a variety of assumptions about the struct ..."
Abstract

Cited by 5 (0 self)
 Add to MetaCart
(Show Context)
The networking research community increasingly seeks to leverage mechanism design to create incentive mechanisms that align the interests of selfish agents with the interests of a principal designer. To apply mechanism design, a principal designer must adopt a variety of assumptions about the structure of the induced game and the agents that will be participating. (We focus in this paper on assumptions regarding agent preferences and nonrepeated vs. repeated games.) As we demonstrate, such assumptions are central to understanding the degree to which theoretical claims based upon mechanism design support architectural design decisions or are useful predictors of realworld system dynamics. This understanding is central to integrating the theoretical results from mechanism design into a larger architectural discussion and engineering analysis required in networking research. We present two case studies that examine how the valid theoretical claims of [7, 18] relate to a larger, architectural discussion. We conclude with a discussion of general criteria for designing and evaluating incentive mechanisms for complex realworld networks like the Internet.