The War of Information

We analyze political campaigns between two parties with opposing interests. Parties pay a cost to provide information to a voter who chooses the policy. The information flow is continuous and stops when parties quit. The parties' actions are strategic substitutes: a party with a lower cost provides more but its opponent provides less information. For voters, the parties' actions are complements and raising the low-cost party's cost may be beneficial. Asymmetric information adds a signaling component in the form of a belief-threshold beyond which unfavorable information is offset by the informed party's decision to continue campaigning.

Information Structures in Optimal Auctions

A seller wishes to sell an object to one of multiple bidders. The valuations of the bidders are privately known. We consider the joint design problem in which the seller can decide the accuracy by which bidders learn their valuation and to whom to sell at what price. We establish that optimal information structures in an optimal auction exhibit a number of properties: (i) information structures can be represented by monotone partitions, (ii) the cardinality of each partition is finite, (iii) the partitions are asymmetric across agents. These properties imply that the optimal selling strategy of a seller can be implemented by a sequence of exclusive take-it or leave-it offers.Optimal Auction, Private Values, Information Structures, Partitions

On the lowest-winning-bid and the highest-losing-bid auctions

Theoretical models of multi-unit, uniform-price auctions assume that the price is given by the highest losing bid. In practice, however, the price is usually given by the lowest winning bid. We derive the equilibrium bidding function of the lowest-winning-bid auction when there are k objects for sale and n bidders with unit demand, and prove that it converges to the bidding function of the highest-losing-bid auction if and only if the number of losers n - k gets large. When the number of losers grows large, the bidding functions converge at a linear rate and the prices in the two auctions converge in probability to the expected value of an object to the marginal winner