Deflation and the trap of falling prices
Why central banks fear falling prices. The deflationary spiral, Fisher debt-deflation, the zero-lower-bound trap, and Japan as the real case.
A short animated lesson on deflation and persistently low inflation, built for Money & Banking students at Western Sydney Vietnam and useful for anyone meeting monetary policy for the first time. It separates deflation, an outright fall in the price level, from disinflation, a slower rise, then builds the three reasons a falling price level is dangerous.
The first is the deflationary spiral, where expected price falls delay spending and invite further cuts. The second is Irving Fisher debt-deflation, where a falling price level raises the real burden of fixed nominal debt. The third is the zero-lower-bound trap, shown through the real-rate identity r = i minus expected inflation. With the nominal rate floored near zero and expected inflation negative, the real rate turns positive and rises, tightening policy exactly when easing is needed.
The lesson anchors all of this to Japan, where deflation set in around 1997 to 1998, consumer prices ran near zero to slightly negative for roughly fifteen years with a trough near minus 0.9 percent in 2002, and the Bank of Japan moved through a zero rate in 1999, quantitative easing in 2001, and a 2 percent target with aggressive easing in 2013. Pair the video with the Atlas concept page for the formula, a worked example, misconceptions, a quick quiz, and citations to Mishkin (2018), Fisher (1933), and Krugman (1998).