Matt Levine entertains the possibility that all money is a ponzi:
"But of course crypto people will happily tell you that fiat currency is the biggest Ponzi scheme of all, and they are not really wrong are they?"
Here is my discussion with some crypto folks on Twitter making that claim.
I disagree. Here is a short (930 words, 3 minutes) blog post explaining why money is not a ponzi.
Aneroid is a small town in Saskatchewan. It has 100 inhabitants. Selma, one of the town's 100 inhabitants, starts a ponzi.
By ponzi, I am referring to a general class of economic phenomena that can only exist if additional people continue to join up. Under these schemes, old investors are paid with new investors' funds. Once the incoming flow of new entrants dries up, the ability to pay out funds to existing participants comes to an end. The scheme ends. This family of economic phenomena includes not only ponzi schemes but also pyramids, chain letters, MLMs, HYIPs, speculative bubbles, and Nakamoto schemes.
Out of the above options, Selma opts to go with a chain letter. She drafts one up on paper and sells a copy to her friends Tom, Sally, and Alice for $10. (I'm replicating the basic design of the notorious 1970s Circle of Gold chain letter). The letter requires the recipient to send $10 to the person at the top of the list, copy the letter (removing the name from the top of the list and writing one's own name at the bottom), and sell it on to three friends for $10.
Selma's chain letter proves to be popular. 99 inhabitants of Aneroid eventually buy a letter, send $10 to the person at the top of the list, and resell it.
But when Jack, the 100th inhabitant, buys a letter and sends $10 to the person at the top, he finds that he can't resell it. Everyone in Aneroid has grown tired of the game. The chain letter stops propagating, the flow of money ceases, and the whole enterprise dies. Jack $10 copy is worthless.
Does money have the same ending as Selma's chain letter?
Enter the Bank of Aneroid.
The Bank of Aneroid is the town's sole issuer of banknotes. The Bank lends a $10 banknote to Selma secured by a $15 lien on her property. Selma spends the $10 note at Frank's hardware store who spends it at the grocery store etc etc, until it ends up in the hands of Jack. But to his dismay Jack finds that, for whatever reason, no one will accept the $10 note.
Alas, poor Jack. His $10 banknote now seems as worthless as his $10 chain letter.
Lucky for him, it isn't. Unlike a chain letter, Jack can return the $10 note to the original issuer, the Bank of Aneroid, for redemption.
Recall that the Bank of Aneroid owns Selma's $10 property-secured IOU. When Jack walks into the Bank and asks to have the note redeemed, the Bank of Aneroid makes good on its promise by selling Selma's debt in the debt market for $10 worth of gold or central bank money. It then pays this amount to Jack. The Bank of Aneroid then destroys its $10 note.
(Alternatively, the Bank of Aneroid can tell Selma to repay her $10 loan, the proceeds being used to pay Jack. Or the Bank can take the more extreme measure of seizing Selma's property and selling it in order to make good on its promise to redeem Jack's $10 banknote.)
As you can see, what I'm describing is not a ponzi scheme. That is, the Bank of Aneroid's $10 banknote isn't valuable because a new buyer keeps arriving to take it off of the previous owner's hands. It is valuable because the original issuer, the Bank of Aneroid, will always repurchase its note using its resources, i.e. its portfolio of loans.
Careful readers will protest at this point. "C'mon JP, you're talking about redeemable bank money. Of course that's not a ponzi. It's the non-redeemable stuff, fiat money, that's a ponzi!"
But I'd argue that the same principles apply to fiat money. I'm going to define fiat money as a banknote that can't be redeemed on demand by its holder into an underlying instrument, perhaps gold or government money.
In our example, let's modify the Bank of Aneroid so that it issues fiat banknotes, not redeemable ones. Apart from that, everything remains the same. Now when Jack takes his unwanted $10 banknote back to the Bank of Aneroid for redemption, the bank refuses to convert it into an underlying medium.
Jack's $10 won't be worthless like the $10 chain letter, though.
"Sorry Jack, we can't redeem it," says the bank manager. "Our banknotes are non-convertible fiat notes. But Selma's $10 loan is due next week. To pay us back she's going to need your $10 note. Why don't you talk with her?"
And so Jack walks over to Selma's house and offers to sell her the $10 note. And Selma will buy it since she'll need it to repay her $10 debt to the Bank.
So in the end, Jack's $10 banknote is valuable—not because a ponzi process props it up—but because the bank that originally issued it reaccepts it. The support that a bank offers to its banknotes is more obvious when a banknote is immediately redeemable by its issuing bank at par. But even an non-redeemable fiat banknote has an underlying linkage back to the issuer that helps support its value.
By contrast, a chain letter (or any other ponzi-like instrument) lacks this connection and only has value as long as a new player emerges.
PS. This note is for Ethereum fans.
Another way to think about the question of fiat money is to bring in some stablecoin analogies. The Bank of Aneroid's non-redeemable fiat notes are equivalent to Rai or MakerDAO's Dai (before Maker introduced the PSM).
Rai and pre-PSM Dai are fiat monies. Neither are directly redeemable into underlying USDC, Tether, or bank dollars. But this doesn't prevent Rai and Dai from staying close to their targets (in Rai's case $3-ish and in Dai's case $1.) In the absence of direct redeemability, the main force pushing these tokens towards target is the requirement that vault owners (i.e. debtors) repurchase Rai and Dai to repay their Rai- and Dai-denominated debts to the system. This is the same force that stabilized the Bank of Aneroid's $10 fiat note in my story. Recall that Frank's $10 note was valuable because Selma needed it to close her debt to the Bank of Aneroid.
Adding an on-demand redemption feature to the Bank of Aneroid's notes only makes this stabilization more direct and immediate, much like Maker's addition of a direct redemption mechanism, the PSM, resulted in a more direct fusion of Dai to its $1 target. (The PSM means that Dai has become non-fiat money.)
Another force keeping Rai and pre-PSM Dai anchored to their respective targets are the threat of Rai's "global settlement" or Maker's "emergency shutdown." Basically, in extreme scenarios both systems can be completely unwound. When this happens all the collateral held in the system gets distributed back to its respective stakeholders, including the owners of Rai and Dai. The knowledge that this could happen helps nudge the price of Rai and Dai closer to their targets.
The Bank of Aneroid's notes are also subject to their own version of emergency shutdown. At any point in time the owners of the Bank of Aneroid can wind up the bank. By collecting on all of their debts, selling those debts to others, or seizing collateral, the Bank can buy back all of the notes they have issued at par. The possibility that this could happen helps pull the Bank of Aneroid's fiat notes towards a stable terminal value.
Sure, there are stablecoins that depend on an underlying ponzi process to stay pegged to $1. But Rai and Dai do not fall into that category of stablecoins. Rai and Dai use non-ponzi mechanisms to create a stable version of the dollar. The Bank of Aneroid's fiat notes are not ponzi-ish for the same reasons that Rai and Dai are not ponzi-ish. And the same goes for Federal Reserve dollars, Bank of Canada dollars, and Bank of England pounds, which operate on the same principles as the Bank of Aneroid's fiat notes.