1. Department of Mathematics and Statistics, Acadia University, Nova Scotia, Canada
2. Department of Statistics, The Wharton School, University of Pennsylvania, Philadelphia, PA, U.S.A.
3. The School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, U.S.A.
4. Department of Information, Risk, and Operations Management, University of Texas at Austin, Austin, TX, U.S.A.