Hyperinflation
The point at which a currency stops being money, conventionally when prices rise more than fifty percent a month. It signals a state that cannot fund itself.
Hyperinflation is what happens when a currency stops being money. The conventional threshold, set by the economist Phillip Cagan in 1956, is prices rising more than fifty percent in a month, which compounds to roughly thirteen thousand percent a year. Below that you have a bad inflation and an unhappy country. Above it you have a society where wages are paid twice a day and spent immediately, where nobody will sell you anything for paper, and where the accumulated savings of everyone who trusted the state are annihilated inside a year.
It is never a monetary accident. It is a fiscal one wearing a monetary costume.
The mechanism
Every case starts with a government whose spending cannot be covered by taxes and cannot be covered by borrowing, usually after a war, a revolution, a collapse in export revenue, or the loss of a productive region. Facing that gap, a government has three options: cut, default, or print. Printing looks painless for a while, because at first people treat the new money as money.
Then expectations flip, and that is the phase change. Once the public believes prices will be higher next week, holding cash becomes irrational. Everyone spends faster, which raises prices, which makes everyone spend faster still. Money velocity, not the printing press alone, is what turns a bad inflation into a vertical one.
The state then discovers a trap. Tax is assessed on last quarter's activity and collected in today's worthless currency, so real revenue collapses as inflation rises, forcing more printing. Economists call this the Olivera-Tanzi effect. It is the reason hyperinflations end abruptly rather than gradually: there is no slow exit, only a new currency and a credible promise to stop.
The reference cases
Germany, 1922 to 1923, is the famous one. Reparations, a war financed almost entirely by borrowing, and then the French occupation of the Ruhr, which Berlin answered by paying strikers with printed money. By November 1923 the dollar was worth about 4.2 trillion marks. It ended in weeks, once the Rentenmark was introduced with a notional backing in land and the printing stopped.
Hungary in 1945 and 1946 was worse, and remains the worst ever recorded: at the peak, prices roughly doubled every fifteen hours, and the pengo had to be replaced entirely.
Zimbabwe in 2008 came third, with official annual inflation reported at 231 million percent in July of that year before the statistics office effectively gave up, and the currency was abandoned for the US dollar in 2009. Yugoslavia in 1993 and Venezuela after 2016 belong on the same list.
What it does politically
The economic damage is severe but the political damage is worse, and it is specific. Hyperinflation destroys the savings of exactly the class that holds money rather than land, businesses, or foreign assets: pensioners, salaried professionals, small rentiers, the people most invested in the existing order. Debtors are relieved and hard assets survive. The middle is wiped out.
That is why it radicalizes. A group that had a stake in the system discovers overnight that the system erased them, and their faith in constitutional politics does not usually recover.
The echo
The German case is routinely mishandled. 1923 did not put Hitler in power; his coup attempt that November failed and the Nazi vote collapsed to under three percent by 1928. What put him in power was the deflationary depression after 1929, with unemployment near a third of the workforce. But 1923 supplied the memory, and the memory did the work: it taught Germans that catastrophe could arrive from the currency, and it left a country that would tolerate almost any hardship rather than another inflation.
That memory is still institutional. The Bundesbank's obsession with price stability, and through it the European Central Bank's mandate, is a direct inheritance from a banknote printed in 1923. Few pieces of paper have had a longer policy afterlife.