1. † Department of Economics, Texas A&M University, College Station, Texas, 77843‐4228, USA. E‐mail:badi@econ.tamu.edu, ssong@mail.korea.ac.kr‡Department of Economics, Korea University, Sungbuk‐Ku, Seoul, 136‐701, Korea. E‐mail:bcjung@kustat.korea.ac.kr