Spectrum auction is an enabling approach for drastically improving the spectrum utilization to satisfy the ever increasing service demands in wireless networks. However, the back-room dealing (i.e., the frauds of the untrustworthy auctioneer and the bid-rigging between the greedy bidders and the insincere auctioneer) makes these applications confront significant security challenges, and fails a...

Combinatorial exchanges are double sided marketplaces with multiple sellers and multiple buyers trading with the help of combinatorial bids. The allocation and other associated problems in such exchanges are known to be among the hardest to solve among all economic mechanisms. In this paper, we study combinatorial exchanges where (1) the demand can be aggregated, for example, a procurement exch...

This article serves as the second part in a two-part series that provides an overview of the reverse auction concept, building on the best research in the field of supply chain management. In this instalment, we look at the concerns involved in making reverse auctions work in practice – the implementation issues. Frist, we look at when reverse auctions should – and should not – be utilized by a...

This paper describes an on-going study analyzing thousands of electronic procurement auctions conducted by a large multinational firm. We describe the challenges of developing metrics for auction success and auction dynamics and how these metrics improve our ability to model, understand, and manage this domain. Since we are in the initial stages of our study and since many of our findings are c...

The bi-objective winner determination problem (2WDP-SC) of a combinatorial procurement auction for transport contracts is characterized by a set B of bundle bids, with each bundle bid b ∈ B consisting of a bidding carrier cb, a bid price pb, and a set τb of transport contracts which is a subset of the set T of tendered transport contracts. Additionally, the transport quality qt,cb is given whic...

We study the combinatorial auction problem, in which a set of objects are to be distributed amongst selfish bidders with the goal of maximizing social welfare. We consider mechanisms that apply greedy algorithms, and ask to what extent truthful greedy mechanisms can find approximate solutions to the combinatorial auction problem. We associate the notion of greediness with a broad class of algor...

Combinatorial auctions are important as they enable bidders to place bids on combinations of items; compared to other auction mechanisms, they often increase the efficiency of the auction, while keeping risks for bidders low. However, the determination of an optimal winner combination in combinatorial auctions is a complex computational problem. In this paper we (i) compare recent algorithms fo...

A VCG auction (named after their inventors Vickrey, Clarke, and Groves) is a generalization of the single-good, second price Vickrey auction to the case of a combinatorial auction (multiple goods, from which any participant can bid on each possible combination). We formalize in this entry VCG auctions, including tie-breaking and prove that the functions for the allocation and the price determin...

A combinatorial auction is an auction that permits bidders to bid on bundles of goods rather than just a single item. Unfortunately, winner determination for combinatorial auctions is known to be NPhard. In this paper, we propose a distributed algorithm to compute optimal solutions to this problem. The algorithm uses nagging, a technique for parallelizing search in heterogeneous distributed com...