Multi-Unit Open Ascending Price Efficient Auction

This paper presents an open ascending price mechanism that allocates efficiently M units of the same good among N bidders with interdependent values The mechanism consists of a number of sequential English auctions with reentry and has the following attributes. In each of the individual auctions all the bidders compete simultaneously in the open ascending price format. The most distinctive feature of the mechanism is that winners are determined first, and then additional auxillary auctions are conducted to determine prices. The total number of auctions depends only on the number of goods to be allocated and not on the number of bidders.Multiple units, Interdependent values, Sequential auctions, Ascending price auction

Investor Sentiments

We consider a general class of games that have been used to model many economic problems where players' sentiments are believed to play an important role. Dropping the common-prior assumption, we identify the relevant notion of sentiments for strategic behavior in these games. This notion is tied to how likely a player thinks that some other player has a more optimistic outlook than himself when they obtain their private information. Under this notion, we show that sentiments have a profound effect on strategic outcomes - even with vanishing uncertainty.

Perfect Implementation

Privacy and trust aect our strategic thinking, yet they have not been precisely modeled in mechanism design. In settings of incomplete information, traditional implementations of a normal-form mechanism - by disregarding the players' privacy, or assuming trust in a mediator - may fail to reach the mechanism's objectives. We thus investigate implementations of a new type. We put forward the notion of a perfect implementation of a normal-form mechanism M: in essence, a concrete extensive-form mechanism exactly preserving all strategic properties of M, without relying on a trusted mediator or violating the privacy of the players. We prove that any normal-form mechanism can be perfectly implemented by a verifiable mediator using envelopes and an envelope-randomizing device (i.e., the same tools used for running fair lotteries or tallying secret votes). Differently from a trusted mediator, a veriable one only performs prescribed public actions, so that everyone can verify that he is acting properly, and that he never learns any information that should remain private

Perfect Implementation of Normal-Form Mechanisms

Privacy and trust affect our strategic thinking, yet they have not been precisely modeled in mechanism design. In settings of incomplete information, traditional implementations of a normal-form mechanism ---by disregarding the players' privacy, or assuming trust in a mediator--- may not be realistic and fail to reach the mechanism's objectives. We thus investigate implementations of a new type.We put forward the notion of a perfect implementation of a normal-form mechanism M: in essence, an extensive-form mechanism exactly preserving all strategic properties of M, WITHOUT relying on a trusted mediator or violating the privacy of the players. We prove that ANY normal-form mechanism can be perfectly implemented by a PUBLIC mediator using envelopes and an envelope-randomizing device (i.e., the same tools used for running fair lotteries or tallying secret votes). Differently from a trusted mediator, a public one only performs prescribed public actions, so that everyone can verify that he is acting properly, and never learns any information that should remain private

Perfect Implementation of Normal-Form Mechanisms

Privacy and trust affect our strategic thinking, yet they have not been precisely modeled in mechanism design. In settings of incomplete information, traditional implementations of a normal-form mechanism ---by disregarding the players' privacy, or assuming trust in a mediator--- may not be realistic and fail to reach the mechanism's objectives. We thus investigate implementations of a new type.We put forward the notion of a perfect implementation of a normal-form mechanism M: in essence, an extensive-form mechanism exactly preserving all strategic properties of M, without relying on a trusted party or violating the privacy of the players.We prove that ANY normal-form mechanism can be perfectly implemented via envelopes and an envelope-randomizing device (i.e., the same tools used for running fair lotteries or tallying secret votes)

Verifiably Secure Devices

We put forward the notion of a verifiably secure device, in essence a stronger notion of secure computation, and achieve it in the ballot-box model. Verifiably secure devices1. Provide a perfect solution to the problem of achieving correlated equilibrium, an important and extensively investigated problem at the intersection of game theory, cryptography and efficient algorithms; and2. Enable the secure evaluation of multiple interdependent functions

On cost overruns in procurement

We consider auctions/tenders for the procurement of goods and services in the setting where the potential contractors face ex-post risks that may lead to cost overruns. The contractors have limited access to credit and are protected by limited liability. We identify the trade-offs that the procurement agency faces in such settings and show that the procuring agency minimizing the expected costs of the project greatly benefits by allocating a share of the award ex-ante, at the time of contracting, with the remainder due ex-post, after the completion of the project