What does deflator mean?
A deflator is a statistical measure, most familiar from economics, that converts nominal values — figures stated at current prices — into real values by stripping out the effect of price inflation. The best-known example is the GDP deflator, which compares an economy's output at current prices with its output at constant prices, revealing how much apparent growth is merely rising prices rather than genuine increases in production. Unlike a fixed-basket index such as the consumer price index, a deflator reflects the changing composition of goods and services actually produced. Outside statistics, the word can denote anything that deflates — literally, a device that removes air, or figuratively, something that punctures enthusiasm or ambition. Deflator belongs chiefly to formal registers: government publications, financial news, and academic analysis. Its usefulness lies in giving economists, policymakers, and businesses a precise way to separate true economic change from the illusion created by inflation.
A factor or index used to remove the effect of price inflation from nominal economic figures, converting them into real terms.
"The implicit price deflator rose faster than expected, signaling broad-based inflation across the economy."
Almost always appears in technical economic contexts and is typically specified by name, e.g. 'GDP deflator' or 'implicit price deflator'.
An agent or thing that deflates; something that removes air or diminishes inflated size, confidence, or enthusiasm.
"The disappointing earnings report served as a deflator of the market's earlier optimism."
This broader or figurative sense is considerably less common than the economic one.
Standard English plural; used when referring to multiple indexes or multiple instances of the thing that deflates.
"Different countries publish their own deflators for adjusting national accounts."
Economists trust the GDP deflator over consumer price indexes because it covers everything an economy produces — not just a fixed shopping basket.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of deflator
Deflator derives from the verb 'deflate', formed in the 19th century from Latin 'flare', meaning 'to blow', with the prefix 'de-' indicating reversal — so literally 'to blow out' or 'to let air out'. The noun follows the standard English agent-noun pattern in '-or'. Its cognates include 'inflate', 'conflate', and other words built on the same Latin root. The economic sense arose in the 20th century as national-income accounting developed and statisticians needed instruments to distinguish real from nominal change.
Related word forms
How deflator is actually used
Predominantly a technical term of economics and statistics, usually found in formal writing such as government reports and financial journalism. The figurative sense — something that dampens enthusiasm — is less common and slightly informal. In technical contexts it is almost always qualified by what it measures, as in 'GDP deflator' or 'implicit price deflator'.
Easily confused with deflator
A 'deflater' is simply something that removes air or reduces pressure (as in data-compression software), while a 'deflator' in economics is specifically an index that strips inflation out of monetary figures.