There are those who believe that the length of a mathematical paper is inversely proportionate to how interesting it is. Something similar can be said about the new paper - short and absolutely first-rate - from Steve Hanke and Nicholas Krus, entitled "World Hyperinflations." It's technically 19 pages long, but the first 12 are basically just throat-clearing, and the last two are references. The meat is the five pages in the middle: three pages of tables, and another two of footnotes, detailing every instance of hyperinflation that the world has ever seen.
Hyperinflation, here, has a clear quantitative definition: prices rising by at least 50% per month. (Remember that, the next time some scaremonger starts talking about how US monetary policy risks causing hyperinflation.) And after some three years' work, Hanke and Krus have managed to come up with an exhaustive list of every hyperinflationary episode in history - 56 in all, or 57 if you include North Korea in early 2010, where the data aren't solid enough to merit inclusion in the list.
Every entry gets its own footnote, and while there are a lot of relatively easy-to-obtain IMF publications in there, there's also no shortage of much more obscure source material: Simeun Vilendecic's Banking in Republika Srpska in the late XX and early XXI century, for instance, or Abram van Heyningen Hartendorp's 1958 History of Industry and Trade of the Philippines.
The earliest hyperinflation on the list came in France, at the end of the 18th Century, when inflation hit a monthly rate of 304% in mid-August 1796. The famous Weimar hyperinflation in Germany is pegged as taking place between August 1922 and December 1923; it reached a monthly peak of 29,500% in October 1923, with prices increasing at 20.9% per day, and doubling every 3.7 days. And the longest period of hyperinflation comes in Greece, which saw hyperinflation for a whopping 55 months, from May 1941 to December 1945. There's no particular reason, looking at this list, why Germany should have been particularly scarred by hyperinflation, to the point at which it fiercely attacks even the possibility of relatively modest inflation, where France and Greece (not to mention Hungary or China or Argentina) have been much less deeply affected.
There is, however, a very strong correlation between the length of time that a period of hyperinflation goes on, and the levels that it can reach at its height. If you look at the top six hyperinflations on the list - which include both Germany and that 55-month period in Greece - all but one lasted for longer than a year. Meanwhile, five of the bottom six hyperinflations took place in just a single month, with the sixth lasting just three months.
At their highest, the numbers start to beggar the imagination: in mid-November 2008, for instance, inflation in Zimbabwe reached a monthly rate of 79,600,000,000%. That's 79 billion percent per month. At that rate, prices pretty much double every day. And Zimbabwe doesn't even manage to grab the top spot: in July 1946, Hungary saw hyperinflation of 41,900,000,000,000,000%. That's 42 quadrillion percent in one month, with prices doubling every 15 hours.
The real value of this paper is its exhaustive nature. By looking down the list you can see what isn't there - and, strikingly, what you don't see are any instances of central banks gone mad in otherwise-productive economies. As Cullen Roche says, hyperinflation is caused by many things, such as losing a war, or regime collapse, or a massive drop in domestic production. But one thing is clear: it's not caused by technocrats going mad or bad.
For that matter, there are no hyperinflations at all in North America: the closest we've come, geographically speaking, was in Nicaragua, from 1986 to 1991. In fact, if you put to one side the failed states of Zimbabwe and North Korea, there hasn't been a hyperinflation anywhere in the world since February 1997, more than 15 years ago, despite the enormous number of heterodox central-bank actions in that time.
All of which is to say that hyperinflation, in and of itself, really isn't anything to worry about. It's pretty much impossible to predict - and if your country has hyperinflation, it almost certainly has even bigger other problems. In fact, I'd hesitate to categorize hyperinflation as a narrowly economic phenomenon at all, as opposed to simply being a symptom of much bigger failures at the geopolitical level. Those failures are exacerbated by hyperinflation, of course: there's very much a vicious cycle in these episodes. But you only ever find hyperinflation under extreme conditions, and, with a single exception (Peru), I'm not even sure I can find any genuine democracies on this list.