Abstract
An open problem is presented regarding the existence of pure strategy Nash equilibrium (PNE) in network congestion games with a finite number of non-identical players, in which the strategy set of each player is the collection of all paths in a given network that link the player’s origin and destination vertices, and congestion increases the costs of edges. A network congestion game in which the players differ only in their origin–destination pairs is a potential game, which implies that, regardless of the exact functional form of the cost functions, it has a PNE. A PNE does not necessarily exist if (i) the dependence of the cost of each edge on the number of users is player- as well as edge-specific or (ii) the (possibly, edge-specific) cost is the same for all players but it is a function (not of the number but) of the total weight of the players using the edge, with each player i having a different weight w i . In a parallel two-terminal network, in which the origin and the destination are the only vertices different edges have in common, a PNE always exists even if the players differ in either their cost functions or weights, but not in both. However, for general two-terminal networks this is not so. The problem is to characterize the class of all two-terminal network topologies for which the existence of a PNE is guaranteed even with player-specific costs, and the corresponding class for player-specific weights. Some progress in solving this problem is reported.
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Anantharam, V.: On the Nash Dynamics of Congestion Games With Player-Specific Utility. In: Proceedings of the 43rd IEEE Conference on Decision and Control, pp. 4673–4678 (2004)
Awerbuch, B., Azar, Y., Epstein, A.: The Price of Routing Unsplittable Flow. In: Proceedings of the 37th Annual ACM Symposium on Theory of Computing, pp. 57–66 (2005)
Beckmann, M., McGuire, C.B., Winsten, C.B.: Studies in the Economics of Transportation. Yale University Press, New Haven (1956)
Christodoulou, G., Koutsoupias, E.: The Price of Anarchy of Finite Congestion Games. In: Proceedings of the 37th Annual ACM Symposium on Theory of Computing, pp. 67–73 (2005)
Diestel, R.: Graph Theory, 3rd edn. Graduate Texts in Mathematics, vol. 173. Springer, Heidelberg (2005)
Even-Dar, E., Kesselman, A., Mansour, Y.: Convergence Time to Nash Equilibria. In: Baeten, J.C.M., Lenstra, J.K., Parrow, J., Woeginger, G.J. (eds.) ICALP 2003. LNCS, vol. 2719, pp. 502–513. Springer, Heidelberg (2003)
Fabrikant, A., Papadimitriou, C., Talwar, K.: The Complexity of Pure Nash Equilibria. In: Proceedings of the 36th Annual ACM Symposium on Theory of Computing, pp. 604–612 (2004)
Fotakis, D., Kontogiannis, S., Spirakis, P.: Selfish Unsplittable Flows. In: DĂaz, J., Karhumäki, J., Lepistö, A., Sannella, D. (eds.) ICALP 2004. LNCS, vol. 3142, pp. 593–605. Springer, Heidelberg (2004)
Fotakis, D., Kontogiannis, S., Spirakis, P.: Symmetry in Network Congestion Games: Pure Equilibria and Anarchy Cost. In: Erlebach, T., Persinao, G. (eds.) WAOA 2005. LNCS, vol. 3879, pp. 161–175. Springer, Heidelberg (2006)
Holzman, R., Law-yone (Lev-tov), N.: Network Structure and Strong Equilibrium in Route Selection Games. Math. Social Sci. 46, 193–205 (2003)
Konishi, H.: Uniqueness of User Equilibrium in Transportation Networks With Heterogeneous Computers. Transportation Sci. 38, 315–330 (2004)
Konishi, H., Le Breton, M., Weber, S.: Pure Strategy Nash Equilibrium in a Group Formation Game With Positive Externalities. Games Econom. Behav. 21, 161–182 (1997)
Koutsoupias, E., Papadimitriou, C.: Worst-Case Equilibria. In: Meinel, C., Tison, S. (eds.) STACS 1999. LNCS, vol. 1563, p. 404. Springer, Heidelberg (1999)
Libman, L., Orda, A.: Atomic Resource Sharing in Noncooperative Networks. Telecommunication Sys. 17, 385–409 (2001)
Milchtaich, I.: Congestion Games With Player-Specific Payoff Functions. Games Econom. Behav. 13, 111–124 (1996)
Milchtaich, I.: Crowding Games are Sequentially Solvable. Internat. J. Game Theory 27, 501–509 (1998)
Milchtaich, I.: Topological Conditions for Uniqueness of Equilibrium in Networks. Math. Oper. Res. 30, 225–244 (2005)
Milchtaich, I.: Network Topology and the Efficiency of Equilibrium. Games Econom. Behav. 57, 321–346 (2006)
Monderer, D., Shapley, L.S.: Potential Games. Games Econom. Behav. 14, 124–143 (1996)
Morgenstern, O., von Neumann, J.: Theory of Games and Economic Behavior, 3rd edn. Princeton University Press, Princeton (1953)
Morris, S., Ui, T.: Best Response Equivalence. Games Econom. Behav. 49, 260–287 (2004)
Papadimitriou, C.H.: Algorithms, Games, and the Internet. In: Proceedings of the 33rd Annual ACM Symposium on Theory of Computing, pp. 749–753 (2001)
Richman, O., Shimkin, N.: Topological Uniqueness of the Nash Equilibrium for Atomic Selfish Routing. Math. Oper. Res. (forthcoming)
Rosenthal, R.W.: A Class of Games Possessing Pure-Strategy Nash Equilibrium. Internat. J. Game Theory 2, 65–67 (1973)
Roughgarden, T.: The Price of Anarchy is Independent of the Network Topology. J. Comput. System Sci. 67, 341–364 (2003)
Roughgarden, T.: Selfish Routing With Atomic Players. In: Proceedings of the 6th Annual ACM-SIAM Symposium on Discrete Algorithms, pp. 1184–1185 (2005)
Roughgarden, T., Tardos, É.: How Bad is Selfish Routing? J. ACM 49, 236–259 (2002)
Roughgarden, T., Tardos, É.: Bounding the Inefficiency of Equilibria in Nonatomic Congestion Games. Games Econom. Behav. 47, 389–403 (2004)
Schmeidler, D.: Equilibrium Points of Nonatomic Games. J. Stat. Phys. 7, 295–300 (1970)
Wardrop, J.G.: Some Theoretical Aspects of Road Traffic Research. In: Proceedings of the Institute of Civil Engineers, Part II, vol. 1, pp. 325–378 (1952)
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Milchtaich, I. (2006). The Equilibrium Existence Problem in Finite Network Congestion Games. In: Spirakis, P., Mavronicolas, M., Kontogiannis, S. (eds) Internet and Network Economics. WINE 2006. Lecture Notes in Computer Science, vol 4286. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11944874_9
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DOI: https://doi.org/10.1007/11944874_9
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