This paper derives comparative static implications of Nash equilibrium bidding in a mineral rights model of auctions. It then tests these implications to assess whether a model of Nash equilibrium behavior in a CV information structure characterizes eBay online computer auctions. Market data is augmented by survey data in order to determine the information structure and bidding behavior in these auctions. This external information permits joint identi…cation of Nash bidding behavior and common values. By imposing structure on the measurement error in my survey data, I am able = =