*  *  *  One of the remarkable economic developments of the past two decades is the sharp, worldwide reduction in rates of inflation. Before the 1980s, research papers, economic commentary, and textbooks here and abroad were full of discussions of the causes and consequences of high inflation and of the political difficulty of bringing it under control.
It looked then like inflation had become a more or less permanent feature of the economic landscape. Concepts associated with deflation such as liquidity traps and the zero bound on nominal interest rates had, for practical purposes, disappeared from economic thought. But, beginning around 1980, central banks around the world seem to have ganged up on inflation, fought the fight, and won.