This paper uses data consisting of students' strategically reported preferences and their underlying true preferences to study the course allocation mechanism used at Harvard Business School. We show that the mechanism is manipulable in theory, manipulated in practice, and that these manipulations cause meaningful welfare losses. However, we also …nd that ex-ante welfare is higher than under the strategyproof and ex-post e¢ cient alternative, the Random Serial Dictatorship. We trace the poor ex-ante performance of RSD to a phenomenon speci…c to multi-unit assignment, "callousness". We draw lessons for the design of multi-unit assignment mechanisms and for market design more broadly.

This paper studies scoring auctions, a procedure commonly used to buy di¤erentiated products:suppliers submit o¤ers on all dimensions of the good (price, level of non monetary attributes), and these are evaluated using a scoring rule. We provide a systematic analysis of equilibrium behavior in scoring auctions when suppliers' private information is multidimensional (characterization of equilibrium behavior and expected utility equivalence). In addition, we show that scoring auctions dominate several other commonly used procedures for buying di¤erenti-ated products, including menu auctions, beauty contests and price-only auctions with minimum quality thresholds.

A buyer seeks to procure a good characterized by its price and its quality from suppliers who have private information about their cost structure (fixed cost and marginal cost of providing quality). We characterize the buyer's optimal buying mechanism. We then use the optimal mechanism as a theoretical and numerical benchmark to study simpler buying procedures such as scoring auctions and bargaining. Scoring auctions can extract a significant proportion of the buyer's strategic surplus (the difference between the expected revenue from the optimal mechanism and the efficient auction). Bargaining does less well and often does worse than the efficient auction.

Bidders' asymmetries are widespread in auction markets. Yet, their impact on behavior and, ultimately, revenue and profits is still not well understood. This paper defines a natural benchmark auction environment to which to compare any private values auction with asymmetrically distributed valuations. The main result is that the expected revenue from the benchmark auction dominates that from the asymmetric auction, both in the first price auction and the second price auction. Moreover, for classes of distributions that lend themselves to a quasi-ordering of more or less asymmetric configurations, we prove that the expected revenue is lower the more asymmetric bidders are. These results formalize the idea that competition is reduced by bidders' asymmetries. Applications to merger analysis, joint bidding and investment are discussed.