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PRODID:-//University of Liverpool Computer Science Seminar System//v2//EN
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DTSTAMP:20260921T212003Z
UID:Seminar-EcCo-1125@lxserverM.csc.liv.ac.uk
ORGANIZER:CN=Nicos 	Protopapas:MAILTO:N.Protopapas@liverpool.ac.uk
DTSTART:20201125T130000
DTEND:20201125T140000
SUMMARY:Economics and Computation Series
DESCRIPTION:Philip Lazos: Truthful mechanisms for two-sided markets\n\nA celebrated impossibility result by Myerson and Satterthwaite shows that any truthful mechanism for two-sided markets that maximizes social welfare must run a deficit, resulting in a necessity to relax welfare efficiency and the use of approximation mechanisms. Such mechanisms in general make extensive use of the Bayesian priors.  In this work, we investigate a question of increasing theoretical and practical importance: how much prior information is required to design mechanisms with near-optimal approximations?\n\n \n\nOur first contribution is a more general impossibility result stating that no meaningful approximation is possible without any prior information, expanding the famous impossibility result of Myerson and Satterthwaite.\n\n \n\nOur second contribution is that one single sample (one number per item), arguably a minimum-possible amount of prior information,  from each seller distribution is sufficient for a large class of two-sided markets. We prove matching upper and lower bounds on the best approximation that can be obtained with one single sample for subadditive buyers and additive sellers, regardless of computational considerations. \n\n \n\nOur third contribution is the design of computationally efficient blackbox reductions that turn any one-sided mechanism into a two-sided mechanism with a small loss in the approximation, while using only one single sample from each seller. On the way, our blackbox-type mechanisms deliver several interesting positive results in their own right, often beating even the state of the art that uses full prior information. \n\nAuthors: Paul Dütting, Federico Fusco, Philip Lazos, Stefano Leonardi and Rebecca Reiffenhäuser\n\nhttps://www.csc.liv.ac.uk/research/seminars/abstract.php?id=1125
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