http://dl.gi.de/handle/20.500.12116/11814 Thu, 23 Jul 2026 14:15:25 GMT 2026-07-23T14:15:25Z http://dl.gi.de/handle/20.500.12116/12531 IT aus der Steckdose: Hype oder Realität? Gentzsch, Wolfgang Sun, 01 Jan 2006 00:00:00 GMT http://dl.gi.de/handle/20.500.12116/12531 2006-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/12527 Reverse procurement and auctions for consumers Klafft, Michael; Spiekermann, Sarah Executive SummaryWeb-based bid invitation platforms and reverse auctions are increasingly used by consumers for the procurement of goods and services. An empirical examination shows that with B-2-C these procurement methods generate considerable benefits for the consumer:⊎ Reverse auctions and bid invitation platforms generate high consumer surplus in the procurement of general and crafts services.⊎ The level of this consumer surplus is affected by the number of bidders. The duration of the auction and the starting price are less important.⊎ In the painting business prices are considerably lower than with traditional procurement channels.⊎ On bid invitation platforms, in most cases (> 55%) the bids with the lowest price are chosen.AbstractWeb-based reverse auctions and bid invitation platforms have been used successfully for the procurement of goods and services in B-2-B and B-2-G contexts for some time. More recently, such procurement tools have become available to consumers and are increasingly gaining in popularity. An empirical examination of more than 1400 bid invitations and over 1100 reverse auctions shows that these two types of platforms generate noteworthy consumer surpluses, with the number of bidders being by far the most relevant factor in the determination of surplus levels. Contrary to traditional auction environments like eBay, auction duration and starting prices turn out to be of little relevance for consumer surpluses, as correlation and regression analyses show. The analysis of procurement data further reveals that consumer-driven platforms are particularly suitable for purchases of crafts and services where they provide an efficient mechanism to bring together buyers and sellers and match supply and demand. An exemplary review of results from painting auctions indicates that the price level achieved by consumers in reverse e-procurement is below reference prices which can be obtained in traditional procurement channels. Being an attractive alternative, reverse e-procurement platforms could bring about a paradigm shift towards buyer-centred e-purchasing. Sun, 01 Jan 2006 00:00:00 GMT http://dl.gi.de/handle/20.500.12116/12527 2006-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/12532 Grid-Computing — Science oder Fiction? Schneider, Marcel Sun, 01 Jan 2006 00:00:00 GMT http://dl.gi.de/handle/20.500.12116/12532 2006-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/12525 Distributed ascending proxy auction — A cryptographic approach Rolli, Daniel; Conrad, Michael; Neumann, Dirk; Sorge, Christoph In recent years, auctions have become a very popular price discovery mechanism in the Internet. The common auction formats are typically centralized in nature. The peer-to-peer paradigm demands gearing up auctions for decentralized infrastructures. In this context, this paper proposes a distributed mechanism for ascending second-price auctions that relies on standard cryptographic algorithms. In essence, the auction protocol has the capability of preserving the privacy of the winning bidder’s true valuation.The auction protocol makes use of a high number of auctioneers divided into several groups. A bidder creates an encrypted chain of monotonously increasing bidding steps, where each bidding step can be decrypted by a different auctioneer group. This considerably reduces the attack and manipulation possibilities of malicious auctioneers. In addition, this secure approach does not require bidders to be online unless they are submitting their bid chain to the auctioneers. Sun, 01 Jan 2006 00:00:00 GMT http://dl.gi.de/handle/20.500.12116/12525 2006-01-01T00:00:00Z