Affiliation: | 1. Department of Economics, Sogang University, Seoul 121-742, Republic of Korea;2. Division of Economics, Hanyang University, Ansan 426-791, Republic of Korea;3. Graduate School of Business, Seoul National University, Seoul 151-916, Republic of Korea;1. Neurology Unit, Medicine Department, Faculty of Clinical Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria;2. Neurology Unit, Department of Medicine, College of Medicine, University of Ibadan, Ibadan, Nigeria |