The danger of 'Deflation' and the need to prevent it

In a paper written by then Governor Ben S. Bernanke on 21 November 2002 to the Federal Reserve, it was mentioned that 'Deflation' must never happen.

The paper is rather lengthy and so I shall cut it short here by just lifting the conclusion here.

Remarks by Governor Ben S. Bernanke
Before the National Economists Club, Washington, D.C.
November 21, 2002

Deflation: Making Sure "It" Doesn't Happen Here

Sustained deflation can be highly destructive to a modern economy and should be strongly resisted. Fortunately, for the foreseeable future, the chances of a serious deflation in the United States appear remote indeed, in large part because of our economy's underlying strengths but also because of the determination of the Federal Reserve and other U.S. policymakers to act preemptively against deflationary pressures. Moreover, as I have discussed today, a variety of policy responses are available should deflation appear to be taking hold. Because some of these alternative policy tools are relatively less familiar, they may raise practical problems of implementation and of calibration of their likely economic effects. For this reason, as I have emphasized, prevention of deflation is preferable to cure. Nevertheless, I hope to have persuaded you that the Federal Reserve and other economic policymakers would be far from helpless in the face of deflation, even should the federal funds rate hit its zero bound.

The writer is now Federal Reserve Chairman.