1. Department of Statistics, University of California-Riverside, Riverside, CA, USA;
2. Department of Economics and Graduate Program in Statistics, McMaster University, Hamilton, Ontario, Canada;
3. Department of Economics and Finance, La Trobe University, Melbourne, Victoria, Australia;
4. Info-Metrics Institute, American University, Washington, D.C., USA;
5. Rimini Center for Economic Analysis, Waterloo, Ontario, Canada;
6. Department of Economics, University of California Riverside, Riverside, CA, USA