I catch both Lars Christensen and Brad DeLong making the claim that an introduction of the drachma will work wonders for Greece. Lars, for instance, says that:
However, Grexit will also remove the monetary straitjacket, which has had caused an enormous amount of economic hardship in Greece since 2008. The removal of this straitjacket will cause a significant easing of Greek monetary conditions, which in my view very likely will cause a sharp rise in nominal GDP in Greece in the coming years.I hate to rain on the party, but even if a drachma is introduced and it collapses in value there won't necessarily be a drachma-induced recovery. Greece is currently in a straitjacket because its monetary standard -- the system for measuring and conveying economic value -- is a euro standard. Think of the euro as being akin to the metric system, a standard for measuring weights and distances, or dots per inch, a standard for measuring print resolution. An introduction of drachmas banknotes into circulation is simply not a sufficient condition to create the sort of effects that Brad and Lars want. To get their recovery, Brad and Lars need an all out monetary standard switch. But as long a Greek prices continue to be expressed in euros, drachmas will simply swim within the existing euro standard fish bowl. All sorts of mountains must be crossed before the penultimate switch of standards. This isn't "snap of the fingers" territory.
Drachma as another bitcoin
To better understand the destiny of a new drachma, its nice to have an example. Lucky for us, we can find one in the recent emergence of one of the world's newest currencies, bitcoin. Now Lars assumes that a collapse in the drachma will have all sorts of beneficial effects on the Greek economy. But does the world economy roar when bitcoin plunges? No, and here's why.
While merchants accept bitcoin as payment, they haven't accepted it as a standard. Sticker prices continue to be set in units like dollars, yen, pounds, etc., Bitcoin swims within the existing fiat standard. To accommodate those who want to pay in bitcoin, merchants will typically use the last-second bitcoin-to-dollar exchange rate (taken from foreign exchange markets) as the basis for the bitcoin price of their goods. Which means that as bitcoin plunges in value, the amount of bitcoin that retailers ask for their stuff is immediately adjusted upwards by a concomitant amount.
This is important because implicit in Brad and Lars's drachma recovery story is a certain degree of price stickiness. As the fundamental value of the standard unit plunges, sticker prices are slow to adjust upwards. Knowing that sticker prices will at some point start to catch up, people spend their currency now before it loses value, thus stoking an economic boom as merchants' inventories are drawn down. This sticky price effect is entirely lacking in bitcoin. Given a sickening collapse in bitcoin, those who own the stuff have no reason to spend it on before it loses value. After all, the amount of bitcoin that retailers require is adjusted every second, so prices in terms of bitcoin don't stay sticky. A bitcoin collapse therefore has no real effects on the world economy.
Applying this lesson to Greece, there's no guarantee that a decline in the drachma will boost the Greek economy. The appearance in circulation of drachma banknotes needn't mean that sticker prices will be set in drachmas. To determine how many drachmas Greeks must pay for an item, retailers may simply refer to its euro sticker prices and convert that amount into drachma by glancing at the last-second drachma-to-euro exchange rate. If so, then just as bitcoin prices are not sticky, neither will drachma prices. Without the requisite stickiness, a collapse in drachmas will not have the real effects that Lars and Brad want. Only a collapse in the euro, the monetary standard, will harness the sticky price effect the two implicitly invoke. But that effectively means Greece remains in its monetary straitjacket, despite having debuted a drachma.
Hurdles to switching
I've talked about the network externalities involved in switching standards before. Take an incumbent standard and a new standard. Even if the quality gap between the novel standard and the inferior incumbent is quite high, the costs of coordinating everyone onto the new standard may be too onerous for adoption to occur. Hysteresis, or lock in, is the result.
Switching to a drachma standard requires that a strong third party step in to overcome these network externalities. They need to punish, or credibly threaten to punish, those who refuse to comply. The Greek government, which has already demonstrated an inability to execute on basic tasks like tax collection, could very well lack the resources that are necessary to adequately perform the tasks of a third party.
Further militating against a drachma standard is its massive quality gap. A monetary standard should be as nuisance-free as possible. Merchants do not want to be adjusting their prices every day, and customers want to know that the blender they saw on a store's shelves on Tuesday will be worth the same amount when they go back on Wednesday. If sticker prices must be adjusted hourly, or even by the minute, the amount of time and mental space that people must allocate to calculation and measurement will displace other more meaningful activities. Like bitcoin, the drachma would probably be a one of the world's most volatile currencies; the incumbent euro one of its steadiest. So rather than improving on the euro standard, a drachma standard would represent a regression in quality.
Given that a strong government must spend a significant amount of resources getting its population to adopt a better standard, it's hard to imagine that a weak government will ever be able to foist an inferior standard on its population without facing a backlash. So contrary to Lars and Brad, there is no guarantee that issuing drachmas offers an ultimate salvation. In the end, there's probably very little difference between a Greece that introduces a drachma or one that doesn't, since either way the incumbent euro standard will likely stick around.
Note: This is very similar to my previous post on the topic. I've introduced the bitcoin analogy, which I think helps drive home the point, and also brought the quality gap to the forefront.
Nick Rowe comments here.