Bounds for the Query Complexity of Approximate Equilibria
@article{Goldberg2013BoundsFT, title={Bounds for the Query Complexity of Approximate Equilibria}, author={Paul W. Goldberg and Aaron Roth}, journal={ACM Transactions on Economics and Computation (TEAC)}, year={2013}, volume={4}, pages={1 - 25} }
We analyze the number of payoff queries needed to compute approximate equilibria of multi-player games. We find that query complexity is an effective tool for distinguishing the computational difficulty of alternative solution concepts, and we develop new techniques for upper- and lower bounding the query complexity. For binary-choice games, we show logarithmic upper and lower bounds on the query complexity of approximate correlated equilibrium. For well-supported approximate correlated…
32 Citations
Query Complexity of Approximate Equilibria in Anonymous Games
- Computer Science, EconomicsWINE
- 2015
It is proved that $$\varOmega n \log {n}$$ payoffs must be queried in order to find any $$epsilon $$-well-supported Nash equilibrium, even by randomized algorithms, which is the first one to obtain an inverse polynomial approximation in poly-time.
Lower Bounds for the Query Complexity of Equilibria in Lipschitz Games
- Economics, MathematicsSAGT
- 2021
This work develops a query-efficient reduction from more general games to Lipschitz games, and provides an exponential lower bound on the deterministic query complexity of finding -approximate correlated equilibria of n-player, m-action, λ-Lipschitzer games for strong values of , motivating the consideration of explicitly randomized algorithms in the above results.
Finding Approximate Nash Equilibria of Bimatrix Games via Payoff Queries
- Economics, Computer ScienceACM Trans. Economics and Comput.
- 2016
It is shown that randomized algorithms require Ω(k2) payoff queries in order to find an ϵ-Nash equilibrium with ϵ < 1/4k, even in zero-one constant-sum games, which rules out query-efficient randomized algorithms for finding exact Nash equilibria.
Logarithmic Query Complexity for Approximate Nash Computation in Large Games
- Economics, Computer ScienceTheory of Computing Systems
- 2018
A randomised algorithm is presented that achieves ε approaching 18$\frac {1}{8}$ for 2-strategy games in a completely uncoupled setting, where each player observes her own payoff to a query, and adjusts her behaviour independently of other players’ payoffs/actions.
Finding approximate nash equilibria of bimatrix games via payoff queries
- Economics, Computer ScienceEC
- 2014
It is shown that randomized algorithms require Omega(k2) payoff queries in order to find a 1/6k-Nash equilibrium, even in zero-one constant-sum games, which rules out query-efficient randomized algorithms for finding exact Nash equilibria.
Settling the Complexity of Computing Approximate Two-Player Nash Equilibria
- Computer Science2016 IEEE 57th Annual Symposium on Foundations of Computer Science (FOCS)
- 2016
We prove that there exists a constant ε > 0 such that, assuming the Exponential Time Hypothesis for PPAD, computing an ε-approximate Nash equilibrium in a two-player (n × n) game requires…
Simple Approximate Equilibria in Games with Many Players
- Economics, Computer ScienceEC
- 2017
This work considers ε-equilibria notions for a constant value of ε in n-player m-action games and proves its equivalence to the well-known Beck-Fiala conjecture from discrepancy theory, the first result that introduces a connection between game theory and discrepancy theory.
Well-Supported vs. Approximate Nash Equilibria: Query Complexity of Large Games
- Computer ScienceITCS
- 2017
It is proved that, for some constant $\epsilon>0$, any randomized oracle algorithm that computes an $\epSilon$-ANE in a binary-action, $n$-player game must make $2^{\Omega(n/\log n)}$ payoff queries.
Smoothed Efficient Algorithms and Reductions for Network Coordination Games
- Computer ScienceITCS
- 2020
The approach combines and generalizes the local-max-cut approaches of [ER14,ABPW17] to handle the multi-strategy case and defines a notion of smoothness-preserving reduction among search problems, which allows for the extension of smoothed efficient algorithms from one problem to another.
Learning Convex Partitions and Computing Game-theoretic Equilibria from Best-response Queries
- Computer ScienceACM Trans. Economics and Comput.
- 2021
Two algorithms for Constant-Dimension Generalised Binary Search provide bounds on the best-response query complexity of computing approximate well-supported equilibria of bimatrix games in which one of the players has a constant number of pure strategies.
References
SHOWING 1-10 OF 36 REFERENCES
Query Complexity of Approximate Equilibria in Anonymous Games
- Computer Science, EconomicsWINE
- 2015
It is proved that $$\varOmega n \log {n}$$ payoffs must be queried in order to find any $$epsilon $$-well-supported Nash equilibrium, even by randomized algorithms, which is the first one to obtain an inverse polynomial approximation in poly-time.
On the communication complexity of approximate Nash equilibria
- Economics, Computer ScienceGames Econ. Behav.
- 2014
Small-Support Approximate Correlated Equilibria
- EconomicsArXiv
- 2013
It is proved that finding an exact correlated equilibrium with smallest possible support is NP-hard under Cook reductions, even in the case of two-player zero-sum games.
Learning equilibria of games via payoff queries
- EconomicsEC '13
- 2013
This work studies a corresponding computational learning model, and the query complexity of learning equilibria for various classes of games, and has the stronger result that an equilibrium can be identified while only learning a small fraction of the cost values.
An Optimization Approach for Approximate Nash Equilibria
- Computer Science, EconomicsWINE
- 2007
An efficient algorithm is provided that computes 0.3393- approximate equilibria, the best approximation till now, based on the formulation of an appropriate function of pairs of mixed strategies reflecting the maximum deviation of the players' payoffs from the best payoff each player could achieve given the strategy chosen by the other.
Simple approximate equilibria in large games
- EconomicsEC
- 2014
It is proved that in every normal form n-player game with m actions for each player, there exists an approximate Nash equilibrium in which each player randomizes uniformly among a set of O(log m + log n) pure actions, and an inverse connection between the entropy of Nash equilibria in the game, and the time it takes to find such an approximation using the random sampling method is established.
Polynomial-time computation of exact correlated equilibrium in compact games
- Computer ScienceEC '11
- 2011
It is shown that the Ellipsoid Against Hope algorithm can be modified to compute an exact correlated equilibrium, and is the first to tractably compute correlated equilibria with polynomial-sized supports; such correlated Equilibria are more natural solutions than the mixtures of product distributions produced previously.
Query Complexity of Correlated Equilibrium
- Economics, Computer ScienceACM Trans. Economics and Comput.
- 2015
A query model in which an n-player game is specified via a black box that returns players' utilities at pure action profiles is considered, establishing that in order to compute a correlated equilibrium, any deterministic algorithm must query the black box an exponential number of times.
Settling the complexity of computing two-player Nash equilibria
- EconomicsJACM
- 2009
We prove that Bimatrix, the problem of finding a Nash equilibrium in a two-player game, is complete for the complexity class PPAD (Polynomial Parity Argument, Directed version) introduced by…