A well-known obstacle to the greater popularity of Bitcoin as a medium of payment is the high volatility of its exchange value. This volatility results from its built-in quantity commitment: because the number of Bitcoins in existence stays on a programmed path, variations in the real demand to hold Bitcoin must be accommodated entirely by variations in its unit value. When demand goes up, there is no quantity increase to dampen the rise in price; and vice-versa for a fall in demand.

Not surprisingly, several cryptocurrency developers have thought of creating a cryptocurrency with a price commitment–namely a pegged exchange rate with the US dollar–rather than a quantity commitment, in hopes of greater popularity. The aim is to create a system in which dollar-denominated payments can be made with the ease, security, and low cost of Bitcoin payments, but without the exchange-rate risk.

New Digital Assets

The development of “Blockchain 2.0” platforms has enabled the launching of a variety of new digital assets, including such dollar-pegged (and euro-pegged and gold-pegged) currencies. As we will see, the histories of early (2014-2016) dollar-pegged cryptocurrencies show a series of flops. But one project, Tether, has become a late-blooming success.

Tether had $55 million in circulation as of March 29, 2017, making it the #13 largest cryptocurrency. To keep this size in perspective, a brick-and-mortar US institution with $55 million in deposits is a tiny bank or a mid-size credit union, and Tether is currently only 1/300th the size of Bitcoin.

The Tether white paper explains in more detail the motivation for developing a dollar-pegged cryptocurrency by listing advantages to individuals using it for dollar-denominated transactions rather than using dollars held in “legacy bank” accounts:

In sum, “Anything one can do with Bitcoin as an individual one can also do with” a dollar-pegged cryptocurrency, namely, “avoid credit card [or debit card] fees,” maintain greater privacy, “remit payments globally” more cheaply, and access blockchain financial services.

But what is the claimed advantage over using Bitcoin? It is the expectation of wider acceptance in payments, because of the advantages to merchants of accepting a dollar-pegged cryptocurrency over accepting Bitcoin in a US-dollar-dominated economy:

The Flops

First we consider the projects that have flopped. Three projects were launched in September 2014: CoinoUSD, NuBits, and BitUSD. Their pegging mechanisms were different, and are difficult to describe briefly (partly because they were not all entirely transparent), but two common features are important to note.