Money: The Unauthorized Biography

six basic units, sufficient for the measurement of any aspect of the physical world: the metre for linear extension, the kilogram for mass, the second for time, the degree Kelvin for temperature, the candela for luminosity, and the ampere for electric current

The fathom was used to record the depth of the sea, while the ell was used in the measuring out of cloth.

Even today in the U.K., whisky is measured in gills, beer in pints, and petrol in gallons

Money is not a commodity medium of exchange, but a social technology composed of three fundamental elements.40 The first is an abstract unit of value in which money is denominated. The second is a system of accounts, which keeps track of the individuals’ or the institutions’ credit or debt balances as they engage in trade with one another. The third is the possibility that the original creditor in a relationship can transfer their debtor’s obligation to a third party in settlement of some unrelated debt.41

money is not a commodity, but a system of credit and clearing.

But currency is not itself money. Money is the system of credit accounts and their clearing that currency represents.

For sellers to accept buyers’ IOUs in payment, they must be convinced of two things. They must have reason to believe that the debtor whose obligation they are about to accept will, if it comes to it, be able to satisfy their claim: they must believe, in other words, that the money’s issuer is creditworthy. This much would be enough to sustain the existence of bilateral credit. The test for money is more stringent. For credit to become money, sellers must also trust that third parties will be willing to accept the debtor’s IOU in payment as well.

Barter, in the strict sense of moneyless market exchange, has never been a quantitatively important or dominant mode of transaction in any past or present economic system about which we have hard information,” wrote the American scholar George Dalton in 1982

the problem with this system of barter exchange is that it was very inefficient. You had to find another person who had exactly what you wanted, and who in turn wanted exactly what you had got—and what is more, both at exactly the same time