Inflation, here, is a decline in the purchasing power of the unit. Prices are the visible surface. Hyperinflation is a special case, not the definition.
What inflation is on this site
The underlying question is whether the stock of money is growing faster than the goods and claims it is asked to measure. An hour of work is a useful check. If the same hour buys less bread, less rent, or less metal over years, the unit has weakened. That can happen with or without a dramatic crisis.
Consumer-price indexes and wholesale indexes are measurement tools. They are not the definition. The definition is purchasing-power erosion of the unit. Indexes help document that erosion; they do not invent it. Basket choice, quality adjustments, and base years matter for reading a series — they do not rewrite the idea.
This page stays on the idea. Weimar 1923 is the documentary extreme. Do not paste Weimar into every mild rise in a price index. Ordinary inflation and hyperinflation share a channel when money stock is discretionary; they do not share a severity or a timeline. A two-percent annual rise and a monthly fifty-percent rise are not the same documentary object.
Money stock and prices
Prices can rise because goods are scarce, because demand shifts, or because more units chase the same things. Hard-money writers emphasise the last channel. A complete account of any year needs all three. This site only needs the distinction: a unit that can be issued without cost makes the last channel a policy choice.
Sound money does not make relative prices stand still. It constrains one source of a general rise. Harvest failures, war damage, and demand shifts still move particular prices under a hard unit. A gold standard that holds convertibility can still see wartime scarcity lift food prices without rewriting the unit.
When the issuer can expand the stock as policy, a fiscal gap can be closed with new units. Tax arrives later in weaker money. Real cash balances fall; people spend faster; velocity rises. That feedback is the mechanical core of severe inflation episodes — stated as mechanism, not as a morality play.
Purchasing power as the check
Ask what a unit buys over time: a basket of goods, an hour of common labor, a weight of metal. If the basket shrinks for the same nominal wage, purchasing power fell. If metal rises sharply in the unit while the metal’s mining cost did not jump overnight, the unit may be the thing that weakened.
Premiums, taxes, and local scarcity still matter for any single price. The purchasing-power check is about the unit across many goods, not one headline. Hard money vs fiat names which units make stock expansion a policy lever.
Greenbacks during the American Civil War traded at a gold premium in New York. That premium was the market’s measure of paper versus metal — a wartime purchasing-power fact, documented on greenbacks and the Civil War. Resumption later closed the gap in practice; the idea page only names what the gap measured.
Interest rates and bond prices can move with inflation expectations — a separate topic. Here the claim stays narrow: purchasing power of the unit is the object; prices are the surface.
Hyperinflation is a case
Hyperinflation is usually marked when prices rise on the order of 50% or more in a month. It is a phase, not a synonym for every inflation. Germany crossed that line in mid-1922; the paper mark then ceased to work as a store of value or a unit of account by autumn 1923.
The cartoons — wheelbarrows, wallpaper notes — are evidence of velocity and refusal to hold balances. They are not the cause. The cause chain on the Weimar page is war finance, a missing gold stop, fiscal gaps, and monetisation of Treasury paper.
Assignats in revolutionary France and Law’s 1720 System are other paper collapses with their own dates and instruments. Rhyme teaches mechanism. Merge erases centuries. Keep them on banks and paper, not as footnotes that rewrite this definition.
Stabilisation after hyperinflation often needs a new unit, a fiscal stop, and a credible refusal to print for the treasury — the Rentenmark story on the Weimar page. That is history. The idea here is only that hyperinflation is inflation’s extreme phase, not its everyday meaning.
What this definition is not
It is not a forecast of next year’s index. It is not a recommendation to buy or sell metal, bonds, or anything else. Information versus advice is the standing line.
It is not a claim that every price rise is “only printing.” Scarcity and demand shifts are real. The job here is to keep the money-stock channel visible when the unit can be issued without a stop.
It is not a substitute for what is sound money?. Sound money names the constraint. Inflation names what happens to purchasing power when the unit weakens — under any regime. It is also not a markets page: dated metal figures live on Markets.
Where to go next
Return to Sound Money. Read with hard money vs fiat and backed money. For the extreme case, open Weimar hyperinflation.
History articles stay documentary. This page only fixes the idea: purchasing power of the unit, prices as surface, hyperinflation as a case. When a reader asks “what does inflation mean?” stay here. When they ask “what happened in 1923?” leave for history.