Bidder coalitions at English auctions frequently distribute collusive gains among members via a secondary auction of "knockout." When coalition members are sufficiently heterogeneous, nested coalition structures are observed in which a knockout is conducted at each level of nesting. The nested...

An experiment analyzing behavior in English common value auctions is reported. English auctions raise more revenue than first-price auctions only when bidders do not suffer from a strong winner's curse. Agents employ other bidders' dropout prices along with their private information as Nash...