Every agent reports his willingness to pay for one unit of a good. A mechanism allocates goods and cost shares to some agents. We characterize the group strategyproof (GSP) mechanisms under two alternative continuity conditions interpreted as tie-breaking rules. With the maximalist rule (MAX) an...

Prosper, today the second largest social lending marketplace with nearly 1.5 million members and $380 million in funded loans, employed an auction mechanism amongst lenders to finance each borrower's loan until 2010. Given that a basic premise of social lending is cheap loans for borrowers, how...

We study the second best in a single unit sale to two bidders. This is the allocation that maximizes the expected social surplus subject to the biddersʼ incentive compatible constraints when the first best is not implementable. We prove that Maskinʼs (1992) result that any first best...

A number of identical objects is allocated to a set of privately informed agents. Agents have linear utility in money. The designer wants to assign objects to agents that possess specific traits, but the allocation can only be conditioned on the willingness to pay and on observable...

In the basic adverse selection model, a seller makes a contract offer to a privately informed buyer. A fundamental hypothesis of incentive theory is that the seller may want to offer a menu of contracts to separate the buyer types. In the good state of nature, total surplus is not different from...

We study the problem of finding the profit-maximizing mechanism for a monopolistic provider of a single, non-excludable public good. Our model covers the most general setting, namely, we allow for correlation in the signal distribution as well as for informational externalities in the...

We study a mechanism design problem in which players can take part in a mechanism to coordinate their actions in a default game. By refusing to participate in the mechanism, a player can revert to playing the default game non-cooperatively. We show with an example that some allocation rules are...

We consider a market for indivisible items with m buyers and m sellers. Traders privately know their values/costs, which are statistically dependent. Two mechanisms are considered. The buyer's bid double auction collects bids and asks from traders and determines the allocation by selecting a...

I examine a contest with identity-dependent rules in which contestants are privately informed and ex ante heterogeneous. A contestant may suffer from a handicap or benefit from a head start. The former reduces the contestantʼs score by a fixed percentage; the latter is an additive bonus....

We study a sealed-bid auction between two bidders with asymmetric independent private values. The two bidders own asymmetric shares in a partnership. The higher bidder buys the lower bidderʼs shares at a per-unit price that is a convex combination of the two bids. The weight of the lower bid is...