1. Department of Agricultural and Consumer Economics, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA; and Regional Economics Applications Laboratory, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA.
2. Interdisciplinary Program in Statistics and Regional Economics and Spatial Modeling Laboratory, University of Arizona, Tucson, AZ, USA.