Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu|Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA. kshedden@umich.edu