"It has so long been treated as a self-evident proposition that the supply of money cannot be left to competition, that probably few people could explain why," says Hayek. The Denationalization of Money is a classic monetary treatise which argues for the superiority of a competitive, private of the monetary system (specifically the monetary supply, issuance, exchange, etc.) over monopolized issuance by governments.
Fundamentally, it would appear that Hayek is arguing that the government monopoly of money is unnecessary, and that in a competitive arena, the primacy rules-based monetary supply over a discretionary one would eventually become apparent. This argument should be eerily familiar to any student of Austrian economics or blockchain enthusiast living in 2018.
For Hayek money is best thought of as a relative adjective rather than a noun. If we empirically observe goods within a marketplace, we learn that there is no clear distinction between money and non-money. There is only a spectrum of objects (or assets) with various degrees of liquidity - where relative value fluctuates independently of each other asset. Price is relative.
In the text, Hayek identifies four core 'uses', or attributes of money:
The first is cash purchases or the ability to spend a given token on a consumption good. With great foresight, Hayek argues that "electronic cash registers would probably be developed rapidly to show instantaneously the equivalent of any price in any any currency desired, [and] also connect through the computer with banks so that firms would immediatly be credited with the equivalent in the currency in which they kept their accounts. We can see this in todays world through mobile payment wallets with built-in centralized exchange mechanisms, like ShapeShift (or more recently, through atomic swap mechanisms and decentralized exchange protocols like 0x).
The second attribute of 'money' is the ability for users to hold reserves for future payments. There are physical components here centered around durability (i.e. will my piece of paper withstand being dipped in water, or more generally the waves of time). There are also intersubjective, faith based concepts like "will people accept this money in the future?", will it hold it's value, etc. Here it would seem the common wage earner would prefer a stablecoin (as described later in the review).
The third defined attribute is as a standard of differed payments, meaning, "do I want to use this money for lending or borrowing". In the digital era, we may see projects like the Dharma Protocol come into play here.
The fourth and final described attribute is as a reliable unit of account. It is here that common monetary concepts like fungibility, divisibility, measurability, etc. come into play.
Translating to post-21 terms, Hayek believes that the winning currency in a competitive market would be one generally expected to preserve its purchasing power approximately constant would be in continuous demand so long as the people were free to use it (aka the Stablecoin Arguement). With the success of the stablecoin dependent on keeping the value of the token constant, one could 'trust' the cryptocurrency developers to achieve this better than any monopolist who runs no risk by depreciating its money. The issuing institution (developer) could achieve this by regulating the quantity of its issue (ala distributed consensus algorithm). Strictly speaking, however, there is no such thing as a 'perfectly stable value of money' - a conclusion which is also reached by Noah Yusaf Harari in the now widely-read Sapiens.
It is a 'legal fiction' that there is one clearly defined thing called 'money' which can sharply be distinguished from other things, argues Hayek, and this assumption has led to misleading conclusions in macroeconomic theory (i.e. - the Quantity Theory of Money). According to Hayek, this 'money illusion' only arose because it was useless for individuals of a particular monetary zone to worry about it so long as they could not do anything about it.
In Hayek's view, "Once people have a choice, they will become very much aware of the different changes of the value of the different currencies accessible to them. It would become common knowledge that money needs to be watched, and would be regarded as a praiseworthy action, rather than an unpatriotic act that a particular currency was suspect."
In my view, given basic human nature, it seems obvious that good national money is impossible under a democratic government dependent on the voting cartels of special interests.
Hayek concludes the essay with a number of short-and-long term paths forward toward a competitive monetary base. He concludes that a 'Free Money Movement' that is comparable to the 'Free Trade Movement' of the 19th century will eventually emerge.
In my opinion, this movement, if it were to emerge, will be more similar to the 'Free and Open Source (FOSS) Software' movement of the late 90's and early 00's - in which free market competitors in the OS arena (namely Linux) emerged to topple the dominant, and primacy of the Windows OS (which was similarly bolstered by an aforementioned 'legal illusion').
This essay is a most read for any cryptoenthusiasist (and may be regarded as core lore along with the works of Szabo, Nakamoto, Buterin, etc.)