1. PhD, Department of Agrifood System Research, Korea Rural Economic Institute 601 Bitgaram-ro, Naju, Jeollanam-do, 58217 South Korea
2. PhD, Department of Agricultural Economics, Purdue University 403 West State Street, West Lafayette, IN 47907 USA
3. Department of Agricultural Economics, Kansas State University 342 Waters Hall, 1603 Old Claflin Plaza, Manhattan, KS 66506 USA