Title
Achieving Target Equilibria in Network Routing Games without Knowing the Latency Functions
Abstract
The analysis of network routing games typically assumes, right at the onset, precise and detailed information about the latency functions. Such information may, however, be unavailable or difficult to obtain. Moreover, one is often primarily interested in enforcing a desirable target flow as the equilibrium by suitably influencing player behavior in the routing game. We ask whether one can achieve target flows as equilibria without knowing the underlying latency functions. Our main result gives a crisp positive answer to this question. We show that, under fairly general settings, one can efficiently compute edge tolls that induce a given target multicommodity flow in a nonatomic routing game using a polynomial number of queries to an oracle that takes candidate tolls as input and returns the resulting equilibrium flow. This result is obtained via a novel application of the ellipsoid method, and applies to arbitrary multicommodity settings and non-linear latency functions. Our algorithm extends easily to many other settings, such as (i) when certain edges cannot be tolled or there is an upper bound on the total toll paid by a user, and (ii) general nonatomic congestion games. We obtain tighter bounds on the query complexity for series-parallel networks, and single-commodity routing games with linear latency functions, and complement these with a query-complexity lower bound applicable even to single-commodity routing games on parallel-link graphs with linear latency functions. We also explore the use of Stackelberg routing to achieve target equilibria and obtain strong positive results for series-parallel graphs. Our results build upon various new techniques that we develop pertaining to the computation of, and connections between, different notions of approximate equilibrium, properties of multicommodity flows and tolls in series-parallel graphs, and sensitivity of equilibrium flow with respect to tolls. Our results demonstrate that one can indeed circumvent the po- entially-onerous task of modeling latency functions, and yet obtain meaningful results for the underlying routing game.
Year
DOI
Venue
2014
10.1109/FOCS.2014.12
Foundations of Computer Science
Keywords
Field
DocType
computational complexity,game theory,graph theory,network theory (graphs),query processing,approximate equilibrium,arbitrary multicommodity settings,edge tolls,ellipsoid method,linear latency functions,multicommodity flow,network routing games,nonatomic congestion games,nonatomic routing game,nonlinear latency functions,oracle,parallel-link graphs,polynomial number,query-complexity lower bound,series-parallel graphs,series-parallel networks,single-commodity routing games,target equilibria,Network routing,Stackelberg routing,approximate equilibria,ellipsoid method,multicommodity flows,tolls
Mathematical economics,Mathematical optimization,Economics,Ask price,Polynomial,Latency (engineering),Network routing,Flow (psychology),Oracle,Multi-commodity flow problem,Ellipsoid method
Conference
Volume
ISSN
Citations 
abs/1408.1429
0272-5428
8
PageRank 
References 
Authors
0.84
21
4
Name
Order
Citations
PageRank
Umang Bhaskar16711.75
Katrina Ligett292366.19
Leonard J. Schulman31328136.88
Chaitanya Swamy4113982.64