Template-type: ReDif-Paper 1.0 Author-Name: Grigorieva Elena Author-Name: Herings P. Jean-Jacques Author-Name: Müller Rudolf Author-Name: Vermeulen Dries Author-workplace-name: METEOR Title: Fraction auctions: the tradeoff between effciency and running time Abstract: This paper studies the sales of a single indivisible object where bidders have continuous valuations. In Grigorieva et al. [13] it was shown that, in this setting, query auctions necessarily allocate inefficiently in equilibrium. In this paper we propose a new sequential auction, called the c-fraction auction. We show c-fraction auctions guarantee approximate efficiency at any desired level of accuracy, independent of the number of bidders. We discuss the running time and the efficiency in the ex-post equilibrium of the auction. We show that by changing the parameter c of the auction we can trade off efficiency against running time. Keywords: operations research and management science; Series: Research Memoranda Creation-Date: 2009 Number: 045 File-URL: http://arnop.unimaas.nl/show.cgi?fid=16598 File-Format: application/pdf File-Size: 449992 Handle: RePEc:unm:umamet:2009045