Fall 2007 Thursday, November 8   Rodney Strachan School of Economics University of Queensland "Divergent Priors and Well-Behaved Bayes Factors" 3:00 Refreshments in 241 Schaeffer Hall 3:30 Talk in 140 Schaeffer Hall Bartlett's paradox has been taken to imply that using improper priors results in Bayes factors that are not well defined, preventing model comparison in this case. We use well-understood principles underlying what is already common practice, to demonstrate that this implication is not true for some improper priors, such as the Shrinkage prior due to Stein (1956). While this result would appear to expand the class of priors that may be used for computing posterior odds, we warn against the straightforward use of these priors. Highlighting the role of the prior measure in the behaviour of Bayes factors, we demonstrate pathologies in the prior measures for these improper priors. Using the concepts developed in this discussion, we then propose a method of employing divergent priors (which are at the limit improper) by setting rules on the rate of diffusion of prior certainty. complete paper

All talks are free and open to the public. To receive colloquium reminders via email, please send a request to statistics@uiowa.edu. The 37th Annual Craig Lectures will be on October 11 and 12. Our speaker this year is Nancy Reid from the University of Toronto. Past colloquia: Spring 2007 | Fall 2006 | Spring 2006 | Fall 2005 | Spring 2005 | Fall 2004 | Spring 2004 | Fall 2003 | Spring 2003 | Fall 2002 | Spring 2002 | Fall 2001 | Spring 2001 | Fall 2000 | Spring 2000 | Fall 1999 | Spring 1999 | Fall 1998 | Spring 1998

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