This paper studies the design of ex ante efficient mechanisms in situations where a single object is for sale, and agents have positively interdependent values and can covertly acquire information at some cost before participating in a mechanism. We find that when the strength of...

We study security-bid auctions in which bidders compete for an asset by bidding with securities whose payments are contingent on the asset's realized value and can covertly acquire information at some cost before participating in an auction. We first consider auctions with ordered securities in...