How Much Can Approximate Equilibria Change the Social Cost of Selfish Routing?
We study approximate Nash equilibria in nonatomic congestion games, with the goal of understanding how much the social cost can change when the equilibrium condition is relaxed. We consider $ε$-approximate Nash equilibria ($ε$-NE), in which each player uses a strategy whose cost is at most $1 + ε$ times the minimum available cost. We compare the social costs of $ε$-NE and exact Nash equilibria.…
We haven't written up this one. arXiv cs.AI has the full story — the link below goes straight to it.