Inflation

Latin inflatio — a swelling, blowing up. From inflare — to blow into, swell. The monetary sense — a general rise in prices — emerged in the 19th century as a metaphor: prices swelling, currency expanding. Earlier monetary disturbances were described as debasement or depreciation rather than inflation.

Measured by indices — the Consumer Price Index, Producer Price Index, and others. Central banks since the 1970s have generally targeted around 2% annual inflation as optimal. Hyperinflation — Weimar Germany, Zimbabwe, Venezuela — shows what happens when monetary discipline collapses. The political assignment of blame for inflation varies by ideology and rarely matches the economic evidence.