, Volume 61, Issue 1, pp 116–140 | Cite as

On the Performance of Approximate Equilibria in Congestion Games

  • George Christodoulou
  • Elias Koutsoupias
  • Paul G. Spirakis


We study the performance of approximate Nash equilibria for congestion games with polynomial latency functions. We consider how much the price of anarchy worsens and how much the price of stability improves as a function of the approximation factor ε. We give tight bounds for the price of anarchy of atomic and non-atomic congestion games and for the price of stability of non-atomic congestion games. For the price of stability of atomic congestion games we give non-tight bounds for linear latencies. Our results not only encompass and generalize the existing results of exact equilibria to ε-Nash equilibria, but they also provide a unified approach which reveals the common threads of the atomic and non-atomic price of anarchy results. By expanding the spectrum, we also cast the existing results in a new light.


Price of anarchy Price of stability Congestion games Algorithmic Game Theory Approximate equilibria Selfish routing 


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • George Christodoulou
    • 1
  • Elias Koutsoupias
    • 2
  • Paul G. Spirakis
    • 3
  1. 1.Department of Computer ScienceUniversity of SaarlandSaarbrückenGermany
  2. 2.Department of InformaticsUniversity of AthensAthensGreece
  3. 3.Computer Engineering and Informatics DepartmentPatras UniversityPatrasGreece

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