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arXiv · 0904.4193

On the Power of Randomization in Algorithmic Mechanism Design

Shahar Dobzinski·Shaddin Dughmi
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Abstract

In many settings the power of truthful mechanisms is severely bounded. In this paper we use randomization to overcome this problem. In particular, we construct an FPTAS for multi-unit auctions that is truthful in expectation, whereas there is evidence that no polynomial-time truthful deterministic mechanism provides an approximation ratio better than 2. We also show for the first time that truthful in expectation polynomial-time mechanisms are \emph{provably} stronger than polynomial-time universally truthful mechanisms. Specifically, we show that there is a setting in which: (1) there is a non-polynomial time truthful mechanism that always outputs the optimal solution, and that (2) no universally truthful randomized mechanism can provide an approximation ratio better than 2 in polynomial time, but (3) an FPTAS that is truthful in expectation exists.

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Shahar Dobzinski, Shaddin Dughmi. 2009-08-24. On the Power of Randomization in Algorithmic Mechanism Design. https://arxiv.org/abs/0904.4193

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