CRCS Lunch Seminar

Date: Monday, September 26, 2011
Time: 12:15pm – 1:45pm
Place: Maxwell Dworkin 119

Speaker: Tanmoy Chakraborty, Harvard CRCS

Title: Comparing Auctions and Posted Pricing Mechanisms in Multi-Unit Auctions

Abstract: Auctions are difficult to organize in many settings, especially those where buyers do not approach the seller at the same time, and run the risk of alienating buyers. Posted pricing mechanisms, that offer take-it-or-leave-it prices to buyers, are more convenient to run, provides price stability, and hence are more commonly observed in practice. Despite their complexity, classical economic theory promises optimal revenue for a monopolistic seller who runs auctions. In this work, we consider multi-unit auctions, and show that sequential posted pricing, where buyers may arrive in an arbitrary order, can perform almost as well as Myerson’s optimal auction when the seller has many items.
When the seller has K identical items is his inventory, we establish a worst-case ratio of (1 – 1/\sqrt(2 \pi K)) between sequential posted pricing and Myerson’s auction when buyers’ valuations are drawn from identical distributions, and a ratio of (1 – \sqrt(ln K / K)) for non-identical distributions. Both bounds go to 1 as K goes to infinity. Further, the bounds solely depend on K, and holds for arbitrary number of buyers and value distributions. We argue that such a guarantee can help a seller commit to posted pricing, without making any assumptions about market demand, if he has a large number of items.

Short Bio: Tanmoy Chakraborty is a postdoctoral fellow at the Center for Research on Computation and Society at Harvard University. He recently completed his PhD from University of Pennsylvania. The title of his dissertation is “Bargaining and Pricing in Networked Economic Systems”. A list of his publications can be found at http://people.seas.harvard.edu/~tanmoy