In another excellent post on Moneyness, J P Koning likens the monetary system to the plot in the movie Inception, featuring
a dream piled on a dream piled on a dream piled on a dream.
Koning explains that
[l]ike Inception, our monetary system is a layer upon a layer upon a layer. Anyone who withdraws cash at an ATM is ‘kicking’ back into the underlying central bank layer from the banking layer; depositing cash is like sedating oneself back into the overlying banking layer.
Monetary history a story of how these layers have evolved over time. The original bottom layer was comprised of gold and silver coins. On top this base, banks erected the banknote layer; bits of paper which could be redeemed with gold coin. The next layer to develop was the deposit layer; non-tangible book entries that could be transferred by order from one person to another.
The foundation layer has changed over time:
One of the defining themes of modern monetary history has been the death of the original foundation layer; precious metals. … as central banks chased private banks from the banknote layer … and then gradually severed the banknote layer from the gold layer. By 1971, … [b]anknotes issued by the central bank had become the foundation layer. The trend towards a cashless world is a repeat of this script, except instead of the gold layer being slowly removed it is the banknote layer.
Fintech improves the efficiency of the layer arrangement and its connections. It also adds new layers: For instance, some payments made via mobile phone effectively transfer claims on deposits. And it may circumvent layers:
In U.K., the Bank of England is considering allowing fintech companies to bypass the banking layer by offering them direct access to the bottom-most central banking layer.
In contrast, a krypto currency like bitcoin establishes a new foundation layer, on which new layers may be built:
Even now there is talk of a new layer being developed on top of the original bitcoin foundation, the Lightning network. The idea here is that the majority of payments will occur in the Lightning layer with final settlement occurring some time later in the slower Bitcoin layer.
I fully agree with this characterization. In addition to the theme emphasized by Koning—adding layers—I would also stress the theme of untying higher-level layers from lower ones: Central bank money typically is no longer backed by gold; deposits typically are not fully backed by notes; and mobile phone credits may no longer be backed by deposits. The process of untying layers relies on social conventions and trust, and it is fragile. Important questions concern the cost of such fragility, and its necessity. Fragility is not necessary when the social cost of liquidity provision at the foundation layer is negligible.