This document discusses concepts in health economics including opportunity costs, production possibilities curves, comparative advantage, and gains from trade. It provides examples showing how specializing production based on comparative advantage and trading can allow both Saudi Arabia and Idaho to gain by producing more of what they have a lower opportunity cost in. Specifically, through trade Saudi could gain 12 more potatoes and Idaho could gain 9 more dates compared to no trade. Overall, the document argues that trade based on comparative advantage provides benefits to all parties.