WEIS is now in its 9th year. Papers from previous workshops are available online.
2007: Carnegie Mellon
Selected papers from WEIS 2002 and WEIS 2003 were published in a recent book, Economics of Information Security, while selected papers from WEIS 2004 appeared in the January 2005 issue of IEEE Security and Privacy. The proceedings from WEIS 2008 were also published in the book Managing Information Risk and the Economics of Security.
For background and more links, see also Ross Anderson's Economics and Security Resource Page, Larry Gordon's Cybersecurity Risk Management links, Alessandro Acquisti's page on the Economics of Privacy, and Jean Camp's Economics of Information Security Bibliography.