Fall 2002 Seminar Series - November 14, 2002
University of Minnesota
School of Statistics
College of Liberal Arts

The In-and-Out-of-Sample (IOS)Likelihood Ratio Test for Model Misspecification

Brett Presnell
Department of Statistics
University of Florida

Thursday, November 14, 2002
4:00 PM, 115 Ford Hall
Minneapolis, East Bank Campus
Social at 3:30 PM, 300 Ford Hall

Abstract

     A new test of model misspecification is proposed, based on the ratio of in-sample and out-of-sample likelihoods. The test is broadly applicable, and in simple problems approximates well-known, intuitive methods. Using jackknife influence curve approximations, it is shown that the test statistic can be viewed asymptotically as a multiplicative contrast between two estimates of the information matrix that are equal under correct model specification. This approximation is used to show that the statistic is asymptotically normally distributed, though it is suggested that p-values be computed using the parametric bootstrap. The resulting methodology is demonstrated with a variety of examples and simulations involving both discrete and continuous data. This is joint work with Dennis Boos of North Carolina State University.