The Robustness of Marginal-Cost Taxes in Affine Congestion Games

The network routing literature contains many results showing that tolls can be used to improve the efficiency of network traffic routing. These results typically require toll-designers to have an exact characterization of the network and user population. We relax this strict informational dependence and present a simple setting in which scaled marginal-cost tolls can be guaranteed to provide significant efficiency improvements over the un-tolled case, even if the toll-sensitivities of the users are unknown.