Deflation

Deflation is a sustained fall in the general price level of goods and services across an economy, so that the same amount of money buys more over time. It is the opposite of inflation and is usually measured by a negative annual reading of a broad price index such as the Consumer Price Index (CPI) or the GDP deflator. A one-off drop in the price of a single product, such as televisions or petrol, is not deflation; the decline has to be broad and lasting.

Deflation is often confused with disinflation, which is a slowdown in the rate of price rises while prices are still going up. Central banks treat persistent deflation as a serious risk because it can deepen a downturn, and most of them aim for low positive inflation, typically about 2%, partly to keep a safety margin above zero. Policy that tries to lift prices back up after a deflationary spell is called reflation.

Imagine a shop where every price tag is quietly marked down a little each month. At first that sounds like good news for shoppers. But if everyone expects the tags to keep falling, many people wait before buying a car, a sofa or a new machine for the business, because waiting means paying less.

When enough people wait, the shop sells less, cuts staff hours and orders less from its suppliers. Those suppliers then cut their own spending. Meanwhile anyone who owes money still owes the same number of dollars, even though their wages and sales are shrinking. That is why economists worry less about a single cheap gadget and more about a whole economy where falling prices feed on themselves.

Economists usually separate deflation into two broad kinds, because the cause matters for whether it is harmful:

• Demand-driven deflation. Spending by households, firms and government falls short of what the economy can produce, often after a financial crisis, a collapse in asset prices or a sharp contraction in the money supply. Firms cut prices to sell unsold output. This is the dangerous kind and is closely linked to recession and depression.
• Supply-driven or "good" deflation. Productivity gains, cheaper technology or a fall in energy and commodity prices push costs down while output grows. Parts of the late nineteenth century under the gold standard saw gently falling prices alongside growth.
• Monetary contraction. When banks fail, credit dries up or a currency is tied to a scarce asset, the amount of money and credit can shrink faster than output, pulling prices down. A strong currency under a fixed exchange rate can import deflation by making imports cheaper.

Three mechanisms explain why central banks fear a deflationary spiral.

The first is the burden of debt. Loans are fixed in money terms, so when prices and incomes fall, the real value of what borrowers owe rises. The American economist Irving Fisher set out this "debt-deflation" theory in 1933: over-indebted borrowers sell assets to repay loans, asset prices fall further, and the distress spreads. Real values of this kind are explained in the entry on real terms.

The second is delayed spending. If households and firms expect prices to keep falling, holding cash becomes attractive and big purchases are postponed, which weakens aggregate demand further.

The third is the limit on interest rates. A central bank normally fights weak demand by cutting its policy rate, but the nominal interest rate cannot fall far below zero. With prices falling, even a zero rate means a positive real rate, which is the reverse of the stimulus needed. This is the problem of the zero lower bound (ZLB) and the related liquidity trap. Sticky wages make matters worse: when employers cannot easily cut pay, falling prices raise real labour costs and lead to job losses instead.

• The Great Depression. In the United States, consumer prices fell by roughly a quarter between 1929 and 1933 as banks failed and the money stock contracted. Many economists, including Milton Friedman and Ben Bernanke, linked the depth of the Great Depression to this deflation and to the gold standard that spread it between countries.
• Japan from the late 1990s. After its asset bubble burst, Japan saw mild but persistent falls in consumer prices for long stretches between about 1998 and 2012. The Bank of Japan used zero interest-rate policy (ZIRP), quantitative easing (QE), a 2% inflation target adopted in 2013 and later negative interest rates and yield curve control before inflation returned in 2022.
• The euro area, 2014–2016 and 2020. Headline inflation dipped below zero at times, prompting the ECB to cut its deposit rate below zero and start large-scale asset purchases.
• China, 2023–2025. Consumer prices hovered around zero; official data showed full-year CPI inflation of 0.0% in 2025, while producer prices fell for the third year running.

The main tools against deflation are monetary and fiscal. Central banks cut rates toward zero, promise to keep them low ("forward guidance") and buy bonds to push down longer-term yields. Many adopted inflation targeting with a positive target precisely to keep the economy away from zero. Governments can add fiscal policy support through spending or tax cuts, which matters most when interest rates are already near their floor.

The debate continues about how costly mild deflation really is. Studies of long historical samples, such as work published by the Bank for International Settlements in 2015, found only a weak link between gently falling consumer prices and slower growth, but a stronger link between falling asset prices, especially property, and weak output. That suggests the cause and setting of deflation matter more than the sign of the price index alone.

• U.S. Bureau of Labor Statistics: Consumer Price Index
• Bank for International Settlements: The costs of deflations, a historical perspective