Kuo I Chang The University of Tokyo   7B538R, Yayoi 1-1-1 , Bunkyo-Ku, Tokyo 113-8657, Japan Tokyo, 113-8657 Japan   aa57090@mail.ecc.u-tokyo.ac.jp         Primary Research Focus: agricultural trade, east asia, gravity model   JEL Areas: N5 : Economic History: Agriculture, Natural Resources, Environment, and Extractive Industries: General, International, or Comparative Q1 : Agriculture: General