Title: Derandomization of Auctions Speaker: Nicole Immorlica, MIT Abstract: In this talk, I will discuss a framework introduced by Goldberg et al. for maximizing revenue in auctions for a good of unlimited supply. Earlier work of Goldberg et al. introduced randomized auction mechanisms that, in the worst case, achieve close to the optimal revenue. We investigate the feasibility of high revenue deterministic auctions. In the process, we give an exponential-space construction for converting any randomized auction to a deterministic one with approximately the same revenue properties. We do so by first proving the existence of a deterministic solution to a related problem, the "hat coloring problem", in which everyone at a party attempts to guess the color of his own hat by just observing the colors of his friends' hats. Our proof draws upon a seemingly unrelated set of techniques from the literature on network flows. We also present a polynomial-time deterministic construction of an auction with good revenue properties, using parity arguments. Our work bypasses an impossibility result of Goldberg et al. for deterministic symmetric auctions by introducing asymmetry into the allocation and pricing scheme, suggesting that in this setting asymmetry is essentially as powerful as randomness. This talk is based on joint work with Gaggan Aggarwal, Amos Fiat, Andrew Goldberg, Jason Hartline, and Madhu Sudan