How does money work?
Gold coins and dollar bills have value only in our common imagination. Their worth is not inherent in the chemical structure of the metal or paper, nor in their color or shape. Money isn’t a material reality—it is a mental construct. It works by converting matter into mind. But why does it succeed? Why should anyone be willing to exchange a fertile rice paddy for a handful of useless gold coins? Why are you willing to flip hamburgers, sell health insurance, or babysit three obnoxious brats when all you get for your exertions is a few pieces of colored paper?
People are willing to do such things when they trust the figments of their collective imagination. Trust is the raw material from which all types of money are minted. When a wealthy farmer sold his possessions for a handful of gold coins and traveled with them to another province, he trusted that upon reaching his destination other people would be willing to sell him rice, houses, and fields in exchange for the gold. Money is accordingly a system of mutual trust, and not just any system of mutual trust: Money is the most universal and most efficient system of mutual trust ever devised. Even people who do not believe in the same god or obey the same king are more than willing to use the same money. Osama bin-Laden, for all his hatred of American culture, American religion, and American politics, was very fond of American dollars.
What created this trust was a very complex and long-term network of political, social, and economic relations. Why do I believe in the gold coin or dollar bill? Because my neighbors believe in them. And my neighbors believe in them because I believe in them. And we all believe in them because our king believes in them and demands them in taxes, and because our priest believes in them and demands them in tithes. Take a dollar bill and look at it carefully. You will see that it is simply a colorful piece of paper with the signature of the US secretary of the treasury on one side, and the slogan “In God We Trust” on the other. We accept the dollar in payment, because we trust in God and the US secretary of the treasury. The crucial role of trust explains why our financial systems are so tightly bound up with our political, social, and ideological systems, why financial crises are often triggered by political developments, and why the stock market can rise or fall depending on the way traders feel on a particular morning.
Initially, when the first versions of money were created, people didn’t have this sort of trust, so it was necessary to define as “money” things that had real intrinsic value. History’s first known money— Sumerian barley money—is a good example. It appeared in Sumer around 3000 BC, at the same time and place, and under the same circumstances, in which writing appeared. Just as writing developed to answer the needs of intensifying administrative activities, so barley money developed to answer the needs of intensifying economic activities.
Barley money was simply barley—fixed amounts of barley grains used as a universal measure for evaluating and exchanging all other goods and services. The most common measurement was the sila, equivalent to roughly one liter. Standardized bowls, each capable of containing one sila, were mass-produced so that whenever people needed to buy or sell anything, it was easy to measure the necessary amounts of barley. Salaries, too, were set and paid in silas of barley. A male laborer earned 60 silas a month, a female laborer 30 silas. A foreman could earn between 1200 and 5000 silas. Not even the most ravenous foreman could eat 5000 liters of barley a month, but he could use the silas he didn’t eat to buy all sorts of other commodities—oil, goats, slaves, and something else to eat besides barley.
Even though barley has intrinsic value, it was not easy to convince people to use it as money rather than as just another commodity. In order to understand why, just think what would happen if you took a sack full of barley to your local mall, and tried to buy a shirt or a pizza. The vendors would probably call security. Still, it was somewhat easier to build trust in barley as the first type of money, because barley has an inherent biological value. Humans can eat it. On the other hand, it was difficult to store and transport barley. The real breakthrough in monetary history occurred when people gained trust in money that lacked inherent value, but was easier to store and transport. Such money appeared in ancient Mesopotamia in the middle of the third millennium BC. This was the silver shekel.
The silver shekel was not a coin, but rather 8.33 grams of silver. When Hammurabi’s Code declared that a superior man who killed a slave woman must pay her owner 20 silver shekels, it meant that he had to pay 166 grams of silver, not 20 coins. Most monetary terms in the Old Testament are given in terms of silver rather than coins. Joseph’s brothers sold him to the Ishmaelites for twenty silver shekels, or rather 166 grams of silver (the same price as a slave woman—he was a youth, after all).
Unlike the barley sila, the silver shekel had no inherent value. You cannot eat, drink, or clothe yourself in silver, and it’s too soft for making useful tools—plowshares or swords of silver would crumple almost as fast as ones made out of aluminum foil. When they are used for anything, silver and gold are made into jewelry, crowns, and other status symbols—luxury goods that members of a particular culture identify with high social status. Their value is purely cultural.
Ultimately, anything can be used as money, provided people have trust in it. Today, most money is just electronic data. The sum total of money in the world is about $60 trillion, yet the sum total of coins and banknotes is less than $6 trillion. More than 90 percent of all money—more than $50 trillion appearing in our accounts—exists only on computer servers. Most business transactions are executed by moving electronic data from one computer file to another, without any exchange of physical cash. Only a criminal buys a house, for example, by handing over a suitcase full of banknotes. As long as people are willing to trade goods and services in exchange for electronic data, it’s even better than shiny coins and crisp banknotes—lighter, less bulky, and easier to keep track of.
For thousands of years, philosophers, thinkers, and prophets have besmirched money and called it the root of all evil. In fact, money is also the apogee of human tolerance. Money is more open-minded than language, state laws, cultural codes, religious beliefs, and social habits. Money is the only trust system created by humans that can bridge almost any cultural gap, and that does not discriminate on the basis of religion, gender, race, age, or sexual orientation. Thanks to money, even people who don’t know each other and don’t trust each other can nevertheless cooperate effectively. For whereas religion asks us to believe in something, money asks us to believe that other people believe in something.
Excerpt from chapter 10, Sapiens: A Brief History of Humankind