The Basics
- Simple definition: The theory that changes in money supply directly cause proportional changes in prices.
- Core idea: More money chasing the same goods leads to inflation.
- Think of it as: Too much money printing makes money less valuable.
What It Actually Means
The quantity theory is expressed as MV = PT (or MV = PY), where M is the money supply, V is the velocity (how fast money circulates), P is the price level, and T or Y is transactions or output. Assuming V and Y are stable, changes in M directly affect P. This theory underlies monetarism – the belief that inflation is always and everywhere a monetary phenomenon.
Example
If Pakistan’s money supply grows 15% while real output grows only 3%, prices will rise about 12% – inflation. This simple relationship guides central banks in setting monetary targets.
Why It Matters (2026)
After years of loose monetary policy globally, inflation returned. The quantity theory reminds us that sustained inflation requires sustained money growth. Central banks now tighten the money supply to control prices.
Don’t Confuse With
Demand for Money – Demand for money is about why people hold cash; quantity theory is about how the money supply affects prices.
See also
Demand for Money • Monetary Policy • Inflation • Velocity of Money • Fisher Equation
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