RT Monograph SR 00 A1 Yamashita, Takuro T1 Revenue guarantees in auctions with a (correlated) common prior and additional information YR 2018 FD 2018-07 VO 18-937 SP 51 K1 Mechanism design K1 Auction K1 Correlated private information K1 Information acquisition K1 Revenue guarantee AB This paper considers auction environments with a (possibly correlated) common prior over bidders' values, where each bidder may have additional information (e.g., through information acquisition). Under certain conditions, we characterize the optimal mechanisms in terms of the expected revenue that is guaranteed given whatever additional information is available to the bidders. Even if the values are correlated,we do not necessarily have full-surplus extraction, and moreover, the optimal mechanism resembles those in the independently distributed cases. Specifically, we show that (i) a second-price auction is optimal among all the efficient mechanisms, and (ii) it is rate-optimal among all the mechanisms. T2 TSE Working Paper PB TSE Working Paper PP Toulouse AV Published LK https://publications.ut-capitole.fr/id/eprint/26151/ UL http://tse-fr.eu/pub/32880