The impact of social ignorance on weighted congestion games

Fotakis, D; Gkatzelis, V; Kaporis, AC; Spirakis, PG

dc.contributor.author	Fotakis, D	en
dc.contributor.author	Gkatzelis, V	en
dc.contributor.author	Kaporis, AC	en
dc.contributor.author	Spirakis, PG	en
dc.date.accessioned	2014-03-01T02:46:33Z
dc.date.available	2014-03-01T02:46:33Z
dc.date.issued	2009	en
dc.identifier.issn	03029743	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/32707
dc.subject	Congestion Game	en
dc.subject	Convergence Rate	en
dc.subject	Independence Number	en
dc.subject	Potential Function	en
dc.subject	Price of Anarchy	en
dc.subject	Price of Stability	en
dc.subject	Nash Equilibria	en
dc.subject.other	Congestion Games	en
dc.subject.other	Convergence rates	en
dc.subject.other	Independence number	en
dc.subject.other	Linear congestion games	en
dc.subject.other	Nash dynamics	en
dc.subject.other	Polynomial-time	en
dc.subject.other	Potential function	en
dc.subject.other	Price of anarchy	en
dc.subject.other	Price of Stability	en
dc.subject.other	Pure Nash equilibrium	en
dc.subject.other	Social graphs	en
dc.subject.other	Strategy selection	en
dc.subject.other	Internet	en
dc.subject.other	Polynomial approximation	en
dc.subject.other	Wine	en
dc.subject.other	Congestion control (communication)	en
dc.title	The impact of social ignorance on weighted congestion games	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1007/978-3-642-10841-9_29	en
heal.identifier.secondary	http://dx.doi.org/10.1007/978-3-642-10841-9_29	en
heal.publicationDate	2009	en
heal.abstract	We consider weighted linear congestion games, and investigate how social ignorance, namely lack of information about the presence of some players, affects the inefficiency of pure Nash equilibria (PNE) and the convergence rate of the ε-Nash dynamics. To this end, we adopt the model of graphical linear congestion games with weighted players, where the individual cost and the strategy selection of each player only depends on his neighboring players in the social graph. We show that such games admit a potential function, and thus a PNE. Our main result is that the impact of social ignorance on the Price of Anarchy (PoA) and the Price of Stability (PoS) is naturally quantified by the independence number α(G) of the social graph G. In particular, we show that the PoA grows roughly as α(G)(α(G)+2), which is essentially tight as long as α(G) does not exceed half the number of players, and that the PoS lies between α(G) and 2α(G). Moreover, we show that the ε-Nash dynamics reaches an α(G)(α(G)+2)-approximate configuration in polynomial time that does not directly depend on the social graph. For unweighted graphical linear games with symmetric strategies, we show that the ε-Nash dynamics reaches an ε-approximate PNE in polynomial time that exceeds the corresponding time for symmetric linear games by a factor at most as large as the number of players. © 2009 Springer-Verlag Berlin Heidelberg.	en
heal.journalName	Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)	en
dc.identifier.doi	10.1007/978-3-642-10841-9_29	en
dc.identifier.volume	5929 LNCS	en
dc.identifier.spage	316	en
dc.identifier.epage	327	en