One of my fondest memories of boarding school is trading—we called it “making deals”. You give me something I want, for something you want. So, if you give me your snacks for a week, I’ll do your chores for a week.
It was somewhat like “trade by barter”.
But as you can imagine, people who could do things better than others (like hair braiding) got many favours. I learned this the hard way and acquired the skill in no time—I, too, wanted to cash in on what people with the talent enjoyed.
To some extent, this is how countries decide what to trade in or spend most of their resources on. As this article explains in detail, countries trade more in areas where they have an advantage. This advantage could either be absolute or comparative.
A country has an absolute advantage if it is better than another country at producing