Extreme macroeconomic states — hyperinflation, depression, and stagflation — are explained by the interaction of money supply changes with self-reinforcing price expectations rather than by money growth alone. The core mechanism is that once output reaches capacity, further increases in the money supply translate into price increases, and expectations of continued price change alter the velocity of money (the number of times a unit of currency is spent per year), producing a feedback loop in either direction: expected inflation accelerates spending and raises inflation further, while expected deflation defers spending, lowers velocity, and deepens price declines into a liquidity trap in which zero nominal interest rates cannot restore borrowing. This belongs to macroeconomics — specifically monetary theory, inflation, and business-cycle pathology — and it establishes the discipline's principle that stabilization policy must manage expectations and confidence, not merely quantities, because aggregate outcomes are the collective result of individually rational anticipatory behavior.
Extreme macroeconomic states — hyperinflation, depression, and stagflation — are explained by the interaction of money supply changes with self-reinforcing price expectations rather than by money gro…