Computer Science – Computer Science and Game Theory
Scientific paper
2009-07-13
Computer Science
Computer Science and Game Theory
Scientific paper
If a two-player social welfare maximization problem does not admit a PTAS, we prove that any maximal-in-range truthful mechanism that runs in polynomial time cannot achieve an approximation factor better than 1/2. Moreover, for the k-player version of the same problem, the hardness of approximation improves to 1/k under the same two-player hardness assumption. (We note that 1/k is achievable by a trivial deterministic maximal-in-range mechanism.) This hardness result encompasses not only deterministic maximal-in-range mechanisms, but also all universally-truthful randomized maximal in range algorithms, as well as a class of strictly more powerful truthful-in-expectation randomized mechanisms recently introduced by Dobzinski and Dughmi. Our result applies to any class of valuation functions that satisfies some minimal closure properties. These properties are satisfied by the valuation functions in all well-studied APX-hard social welfare maximization problems, such as coverage, submodular, and subadditive valuations. We also prove a stronger result for universally-truthful maximal-in-range mechanisms. Namely, even for the class of budgeted additive valuations, which admits an FPTAS, no such mechanism can achieve an approximation factor better than 1/k in polynomial time.
Dughmi Shaddin
Fu Hu
Kleinberg Robert
No associations
LandOfFree
Amplified Hardness of Approximation for VCG-Based Mechanisms does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Amplified Hardness of Approximation for VCG-Based Mechanisms, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Amplified Hardness of Approximation for VCG-Based Mechanisms will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-100053