Several important auction settings, including treasury auctions in Canada and the U.S., have the feature that some bidders (dealers) observe the bids of a subset of other bidders (customers). Quantifying the economic advantage that informationally advantaged bidders derive from this...

We develop a test for common values in auctions in which some bidders possess information about rivals’ bids. This information causes a bidder to bid differently when she has a private value than when her value depends on rivals’ information. In a divisible good setting, such as treasury...