Typography

A few centuries ago, lack of fungibility used to be a big weakness of monetary systems. But technological and legal developments eventually solved the problem. Nascent systems like bitcoin are finding that they must wrestle all over again with fungibility issues. Fungibility exists when one member of a population of items is perfectly interchangeable with another. So for instance, because your grain of wheat can be swapped out with my grain without causing any sort of change to our relative status, we would say that wheat grains are fungible. Fungibility is a desirable property of a monetary system. If all monetary items are interchangeable, then trade can proceed relatively smoothly. If monetary items are not fungible, then sellers cannot accept the monetary item without pausing for a few moments to verify and assay it, and this imposes frictions on trade.    In this post I argue that there are two ways for something to be fungible. They can be fungible for physical reasons or for leg...

In many parts of the world, cash held in ATMs or in cash-in-transit vehicles is protected by so-called intelligent banknote neutralization technology . When a thief tries to force the ATM open, plastic packs filled with dye explode, spraying both the thief and the banknotes. These notes have now been demarcated as stolen. A shopkeeper may refuse to accept marked notes or may only accept them at a large discount to their face value. At this point, cash has ceased to be fungible. One banknote is not a perfect substitute for another. The dye used in banknote neutralization is often mixed with a taggant , a chemical marker that contains a unique combination of elements chosen from thirty or so rare earth metals. This ensures that a given block of cash is protected by a one-of-its-kind dye pack. So if the authorities apprehend the ink-stained thief with the marked cash, they can actually trace the stuff back to its original owner and return it. This incentivizes any would-be ATM thief to th...

The check used to buy Alaska ( source ) I recently read an FP article about the odd persistence of the cheque as a way to make payments. According to the author, even though cheques are slow and cumbersome, people are willing to live with these drawbacks because they like the ability to write messages in the memo field. Competing electronic payments options (in Canada at least) don't have the ability to write memos.   Why do people still use checks? It's the memo field, apparently: https://t.co/ui0D0oTHEI pic.twitter.com/lkpEr9ZpEk — JP Koning (@jp_koning) June 21, 2017 As someone pointed out to me on Twitter, in the U.S. the cheque's memo field is more than just a place for writing personal reminders. According to the law in certain states , when you disagree with your creditor about how much is owed—say the contractor who is building your deck has spent too much on materials—by writing out a cheque for less than the agreed amount and including "paid in full" in...

No, I'm not talking about sound money in the sense of having a stable value. I'm talking about money that is sound because it can survive natural disasters, human error, terrorist attacks, and invasions. Kermit Schoenholtz & Stephen Cecchetti , Tony Yates , and Michael Bordo & Andrew Levin ( pdf ) have all recently written about the idea of CBDC, or central bank digital currency, a new type of central bank-issued money for use by the public that may eventually displace banknotes and coin. Unlike private cryptocoins such as bitcoin, the value of CBDC would be fixed in nominal terms, so it would be very stable—much like a banknote.* It's interesting to read how these macroeconomists envision the design of a potential CBDC. According to Schoenholtz & Cecchetti, central banks would provide "universal, unlimited access to deposit accounts." For Yates this means offering "existing digital account services to a wider group of entities." As for Lev...

David Birch recently grumbled about people's sloppy use of the term legal tender , and I agree with him. As Birch points out, what many of us don't realize is that shopkeepers have every right to refuse to accept legal tender such as coins and notes. This is because legal tender laws only apply to debts, not to day-to-day transactions. If someone has borrowed some money from you, for instance, then legal tender laws dictate a certain set of media that you cannot refuse to accept to settle that debt. These laws have been designed to protect your debtor from a situation in which you demand payment in a rare medium of exchange, say dinosaur bones, effectively driving them into bankruptcy. Conversely, they also protect you the lender from being paid in an inconvenient settlement medium. In Canada, for instance, a five cent coin is legal tender, but only up to $5. If your debtor wants to pay off a $10,000 debt using a truckload of nickels, you can invoke legal tender laws and tell ...