There appears to be little or nothing in the monetarists' handbook to enable them to assess the risk of a loss of confidence in the purchasing power of a paper currency. Furthermore, since today's macroeconomists have chosen to deny Say's Law¹, otherwise known as the laws of the markets, they have little hope of grasping the more subtle aspects of the role of money in price formation. It would appear that this potentially important issue is being ignored at a time when the Eurozone faces growing systemic risks that could ultimately challenge the euro's validity as money.

The euro is primarily vulnerable because it has not existed for very long and its origin as money was simply decreed. It did not evolve out of marks, francs, lira or anything else; it just replaced the existing currencies of member states overnight by diktat. This contrasts with the dollar or sterling, whose origins were as gold substitutes and which evolved in steps over the last century to become standalone unbacked fiat. The reason this difference is important is summed up in the regression theorem.

The theorem posits that money must have an origin in its value for a non-monetary purpose. That is why gold, which was originally ornamental and is still used as jewelry endures, while all government currencies throughout history have ultimately failed. It therefore follows that in the absence of this use-value, trust in money is fundamental to modern currencies.

The theorem explains why we can automatically assume, for the purposes of transactions, that prices reflect the subjective values of the goods and services that we buy. This is in contrast with money that is not consumed but merely changes hands, and both parties in a transaction ascribe to money an objective value. And this is why the symptoms of monetary inflation are commonly referred to as rising prices instead of a fall in the purchasing power of money.

The European Central Bank (ECB) is plainly assuming the euro is money on a par with any other major currency with a longer history. Despite caution occasionally expressed by sound-money advocates in Germany's Bundesbank, the ECB is aggressively pursuing monetary policies designed to weaken its currency. For example, it has reduced its deposit rate for Eurozone banks to minus 0.2%. This is wholly unnatural in a world where possession of money is always more valuable than an IOU. Furthermore banks are encouraged to limit their customers' cash withdrawals, often under the guise of fighting tax evasion or money laundering. But in Greece restrictions on cash withdrawals are clearly designed to protect the banks.

So far, there is nothing identified in this article that actually points to a destabilisation of the euro, other than it's generally a bad idea to fool around with peoples' rights to it. But lets assume for a moment that Greece defaults. In that case the Greek banking system would certainly collapse (assuming the ECB suspends its emergency liquidity assistance (ELA) because bad debts already on their balance sheets exceed tangible equity by a substantial margin. If that assistance is withdrawn, some €80bn of ELA will be lost. Furthermore, TARGET2² settlement imbalances at the other Eurozone central banks, which have arisen through capital flight from Greece and which are guaranteed by the ECB, total a further €42bn. This leaves the ECB in the hole for €122bn. Unfortunately, the ECB's equity capital plus reserves total only €96bn, so a Greek default would expose the euro's issuing bank to be woefully under-capitalised.

Therefore, if Greece defaults we would at least expect the validity of this relatively new euro to be challenged in the foreign exchange markets. Even if the ECB decided to rescue what it could from a Greek default by rearranging the order of bank creditors in its favour through a bail-in, it would still have to make substantial provisions from its own inadequate capital base. For this reason, rather than risk exposing the ECB as undercapitalised, it seems likely that Greece will be permitted to win its game of chicken against the Eurozone, forcing the other Eurozone states to come up with enough money to pay off maturing debt and cover public sector wages. So will that save the euro?

Perhaps it will, but if so maybe not for long. If the Eurozone's finance ministers give in to Greece, it will be harder for other profligate nations to impose continuing austerity. Anti-austerity parties, such as Podemas in Spain, are increasingly likely to form tomorrow's governments, and Spain faces a general election later this year. Prime Minister Renzi and President Hollande in Italy and France respectively are keen to do away with austerity and increase government spending as their route to economic salvation. Unfortunately for both the undercapitalised ECB and its young currency, they are increasingly likely to be caught in the crossfire between the Northern creditors and the profligate borrowers in the South.

Even if Greece is to be saved from default, the ECB will need to strengthen the Greek banks. This is likely to be done in two ways: firstly by forcing them to recapitalise with or without bail-ins, and secondly to restrict money outflows through capital controls and harsh limits on depositor withdrawals if need be. Essentially it is back to the Cyprus solution.

Whichever way Greece is played, Eurozone residents will see themselves having a currency that is becoming increasingly questionable. The bail-in debacle that was Cyprus is still etched in depositors' minds. Cyprus certainly has not been forgotten in Greece, where ordinary people are now resorting to buying mobile capital goods that can be easily sold, such as German automobiles, with the bank balances that cannot be withdrawn in cash and are otherwise at risk from a Cyprus-style bail-in. Greek depositors have realised that euro balances held in the banks are not reliably money. Folding cash is still money, but that is all, and furthermore the folding stuff is rationed.

The next blow for the euro could come from the exchange rate. If the euro continues to lose purchasing power on the foreign exchanges, it is likely to undermine confidence on the ground. And when that happens it will be increasingly difficult for the ECB to retrieve the situation and maintain the euro's credibility as money. It just doesn't seem sensible to take such enormous risks with a currency that has existed for only thirteen years.

¹'Say's Law Of Markets' An economic rule that says that production is the source of demand. According to Say's Law, when an individual produces a product or service, he or she gets paid for that work, and is then able to use that pay to demand other goods and services.

²TARGET2 is an interbank payment system for the real-time processing of cross-border transfers throughout the European Union. TARGET2 replaced TARGET (Trans-European Automated Real-time Gross Settlement Express Transfer System) in November 2007.