1. comparative advantage
   1. more
      1. specialize?
   2. less
      1. specialize?
2. countries
   1. America
      1. agriculture
      2. advantage
         1. natural
   2. China
      1. toys
      2. advantage
         1. labor
   3. Japan
      1. cars
      2. advantage
         1. labor
         2. capital
         3. entrep
   4. Columbia
      1. coffee beans
      2. advantage
         1. natural