Improved Approximation Ratio for Strategyproof Facility Location on a Cycle
Improved Approximation Ratio for Strategyproof Facility Location on a Cycle
Krzysztof Rogowski, Marcin Dziubiński
Proceedings of the Thirty-Fourth International Joint Conference on Artificial Intelligence
Main Track. Pages 4032-4039.
https://doi.org/10.24963/ijcai.2025/449
We study the problem of design of strategy-proof in expectation (SP) mechanisms for facility location on a cycle, with the objective of minimizing the sum of costs of n agents. We show that there exists an SP mechanism that attains an approximation ratio of 7/4 with respect to the sum of costs of the agents, thus improving the best known upper bound of 2 - 2/n in the cases of n ≥ 5. The mechanism obtaining the bound randomizes between two mechanisms known in the literature: the Random Dictator (RD) and the Proportional Circle Distance (PCD) mechanism of Meir (2019). To prove the result, we propose a cycle-cutting technique that allows for estimating the problem on a cycle by a problem on a line.
Keywords:
Game Theory and Economic Paradigms: GTEP: Mechanism design
Game Theory and Economic Paradigms: GTEP: Auctions and market-based systems
Game Theory and Economic Paradigms: GTEP: Noncooperative games
Multidisciplinary Topics and Applications: MTA: Economics
