1. Center for International Area Studies, Hankuk University of Foreign Studies-Seoul, 107, Imun-ro, Dongdaemun-gu, Seoul 02450, Republic of Korea
2. Department of Applied Economics, University of Missouri-Columbia, Columbia, MO 65211, USA
3. Department of Agricultural Economics, Chungnam National University, 99, Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea