Prices and money / evidence guide
Inflation, Currency Depreciation, and the Claim of Causation
Currency moves can affect import prices, but inflation outcomes also depend on demand, wages, margins, expectations, and policy.
Claims that inflation is “impossible” without currency devaluation are stronger than the evidence usually permits. Exchange rates matter because imported goods, energy, and intermediate inputs enter domestic prices. They are not the only route by which a price level can rise.
This is a new analytical guide at a historically used address. It does not preserve the former article or its authorship.
Define the prices first
Consumer-price inflation, producer prices, import prices, wages, and asset prices measure different things. A currency can strengthen against one trading partner and weaken against another. A useful test therefore pairs the price index with a trade-weighted exchange-rate measure and the same observation window.
An isolated bilateral rate can give the wrong impression when trade is diversified.
Trace the pass-through chain
Currency depreciation can raise the local-currency cost of imports. The effect on final prices depends on several steps:
- how much production relies on imported inputs;
- whether suppliers hedge their currency exposure;
- whether firms absorb costs in margins;
- how quickly contracts reset;
- whether demand lets firms raise prices; and
- how inflation expectations and wages respond.
Pass-through can be incomplete and delayed. It can also differ between a temporary currency move and a persistent change.
Test other mechanisms
Domestic demand can outrun available supply. Energy or food supply can contract. Taxes and administered prices can change. Wages and margins can move even when a broad currency index is stable. These mechanisms do not prove that the exchange rate was irrelevant. They show why “necessary” is a demanding word.
The Bank for International Settlements statistics include effective exchange-rate data. National statistical offices and central banks provide price components and policy records. Use release vintages when possible because both seasonal adjustments and weights can change.
Prefer contribution language
The defensible question is not whether a currency move single-handedly caused inflation. Ask how much it contributed, through which components, with what lag, and compared with which alternative mechanisms.
The conclusion should identify uncertainty. A correlation during one episode does not establish a stable rule for every developed economy or period.