Deflation is a sustained decrease in the general price level of goods and services, resulting in increasing purchasing power of money. While cheaper prices may sound beneficial, deflation is widely feared by economists because it can trigger a self-reinforcing downward spiral.

The Deflationary Spiral

When prices fall, consumers delay purchases expecting even lower prices → businesses see declining revenues → they cut wages and jobs → consumers have less income and spend even less → prices fall further. Breaking this cycle is extremely difficult once it takes hold.

Why Central Banks Fear Deflation More Than Inflation

Inflation can be combated with higher interest rates (no theoretical limit). Deflation requires lowering rates, but the zero lower bound limits this tool. Even unconventional tools like QE and negative interest rates have proven less effective at fighting deflation than rate hikes are at fighting inflation.

Japan's Lost Decades — The Cautionary Tale

Japan experienced persistent deflation/near-zero inflation from 1999 to 2022. CPI was negative or barely positive for over two decades despite massive fiscal stimulus, QE, negative interest rates (-0.1%), and yield curve control. GDP barely grew. Japan's experience is the primary reason central banks are so aggressive in preventing deflation.

Historical Episodes

Debt-Deflation

Economist Irving Fisher's 'debt-deflation' theory explains why deflation is devastating: as prices fall, the real value of debt increases, making it harder for borrowers to repay, leading to defaults, bank losses, and deeper economic contraction.