Simultaneous auctions are (almost) efficient

@inproceedings{Feldman2013SimultaneousAA,
title={Simultaneous auctions are (almost) efficient},
author={M. Feldman and Hu Fu and N. Gravin and Brendan Lucier},
booktitle={STOC '13},
year={2013}
}
Simultaneous item auctions are simple and practical procedures for allocating items to bidders with potentially complex preferences. In a simultaneous auction, every bidder submits independent bids on all items simultaneously. The allocation and prices are then resolved for each item separately, based solely on the bids submitted on that item. We study the efficiency of Bayes-Nash equilibrium (BNE) outcomes of simultaneous first- and second-price auctions when bidders have complement-free (a.k… Expand
128 Citations

Tables and Topics from this paper

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References

SHOWING 1-10 OF 34 REFERENCES
Simultaneous Single-Item Auctions
• Economics, Computer Science
• WINE
• 2012
A thorough understanding of the price of anarchy, as a function of the single-item auction payment rule, is provided and a strong optimality result for the canonical second-price auction is proved. Expand
Uniform Price Auctions: Equilibria and Efficiency
• Economics, Computer Science
• Theory of Computing Systems
• 2014
This work provides the first (constructive) proof of existence of pure Nash equilibria in undominated strategies and the first performance evaluation (with respect to economic efficiency) of this popular auction format. Expand
Welfare guarantees for combinatorial auctions with item bidding
• Computer Science, Mathematics
• SODA '11
• 2011
It is proved that under a standard "no overbidding" assumption, for every subadditive valuation profile, every pure Nash equilibrium has welfare at least 50% of optimal --- i.e., the POA is at most 2. Expand
Pure and Bayes-Nash Price of Anarchy for Generalized Second Price Auction
• Economics, Computer Science
• 2010 IEEE 51st Annual Symposium on Foundations of Computer Science
• 2010
This paper is the first to prove bounds on the price of anarchy, and to give any bounds in the Bayesian setting, and exhibits a combinatorial structure of Nash equilibria and uses this structure to bound the priceof anarchy. Expand
On the efficiency of equilibria in generalized second price auctions
The proof exploits the equilibrium conditions developed in [16] and follows by a detailed reasoning about the structure of equilibria and a novel relation of the price of anarchy to the objective value of a compact mathematical program. Expand
Auctions of Heterogeneous Objects
Abstract Simultaneous sealed bid auctions of heterogeneous objects are analyzed. Each bidder's reservation value for an object depends upon the other objects he obtains. Bidders' reservation valuesExpand
Price of anarchy for greedy auctions
• Computer Science, Economics
• SODA '10
• 2010
A simple deterministic mechanism for general combinatorial auctions that obtains an O(√m) approximation at every Bayes-Nash equilibrium (BNE) is exhibited. Expand
Conditional equilibrium outcomes via ascending price processes with applications to combinatorial auctions with item bidding
• Economics, Computer Science
• EC '12
• 2012
This paper studies a relaxed notion, "conditional equilibrium", that requires individual rationality and "outward stability", and asks what is a maximal valuation class that ensures the existence of a conditional equilibrium and includes unit-demand valuations. Expand
GSP auctions with correlated types
• Economics, Computer Science
• EC '11
• 2011
It is demonstrated that the Bayesian Price of Anarchy of the GSP auction is bounded by \$4, even when agents have arbitrarily correlated types, which highlights a connection between the G SP mechanism and the concept of smoothness in games, which may be of independent interest. Expand
Non-price equilibria in markets of discrete goods
• Economics, Computer Science
• EC '11
• 2011
An analysis of the welfare properties of mixed-Nash equilibria of the market viewed as a game shows that while pureEquilibrium are always perfectly efficient, mixedEquilibria need not be, and upper and lower bounds on their amount of inefficiency are provided. Expand