Exchange and subjective value
With the pole, the axe and a boat you have built, you go exploring. You reach a nearby island where a man picks coconuts by hand, just as you did at the start. He has no tools, so he produces little and every coconut costs him a lot.
You have never tasted a coconut. He has never seen a banana. You offer him five bananas for a coconut. Five bananas cost you little, you pick hundreds a day. To him they are worth more than a coconut that costs him so much effort. You both accept and you both come out ahead.
This is fundamental: in a voluntary exchange both sides gain. Not because one cheats the other, but because value is subjective. You value the coconut more than the five bananas and he the other way round. Each receives something worth more, to him, than what he gives up.
Marginal utility
The less you have of something, the more you value each extra unit. If you have no phone, getting one changes your life. If you already have one, a second matters little. It works the same with food, with time and with money, which is no more than a market good subject to the same laws.
There is something important here for investing: where trade is freer, more wealth is created, because resources go to whoever values them most and uses them best. In the Heritage Foundation’s 2026 Index of Economic Freedom, Singapore is first in the world and Switzerland second.
The spontaneous origin of money
With more people and more islands, barter gets complicated: you have to find someone who has what you want and who also wants exactly what you have. It is slow.
The solution emerges on its own, with nobody planning it. People start accepting not only what they need to consume, but something everyone wants, easy to keep, to carry and to divide, so they can swap it later for what they are really after. Murray Rothbard calls it indirect exchange, and that is where money is born.
No government invented money. It came out of the market because it solved a real problem.
A history of money
Each society found on its own the easiest good to trade in its surroundings and used it as money: grain, salt, shells, spices. Through centuries of trial and error, two metals won that contest in societies with no contact with each other: gold and silver. Not by decree, but because of their properties: scarce, durable, divisible, identical in every piece and hard to fake.
In the Middle Ages this was plain to see. Coins from many kingdoms circulated at once, and merchants accepted the ones they trusted most, the ones of good alloy, with the metal they claimed to contain. The bad ones stayed at home and the good ones travelled the world. It was monetary competition, and quality decided which money survived.
How we lost it
Rulers discovered that controlling the currency meant controlling everyone’s wealth. First they minted coins with less metal than they claimed and kept the difference. With paper money the system was perfected: receipts were issued promising gold, and over time more receipts were issued than there was gold.
The final step came in 1971. Nixon suspended the convertibility of the dollar into gold, which since Bretton Woods, in 1944, had held up the world’s monetary system. Since then no government currency has had any backing. Its demand comes from the law, which forces you to accept it and to pay your taxes in it, not from people choosing it.
It is no historical accident. It is what happens when someone has a monopoly on the currency: whoever controls issuance controls the purchasing power of everyone’s savings, and has every incentive to issue more.
Next: Module 3. The modern financial system: the politicians’ philosopher’s stone. Course contents.