My great uncle Phil from Marblehead Massachusetts used to talk about a question on a sailing safety examination he once took: "What should you do if you are caught on a lee shore in a hurricane?" The correct answer was: "You never get caught on a lee shore in a hurricane!" The answer to the question of what you should do when conventional monetary policy is tapped out and you are at the zero interest rate nominal bound is that you should never get in such a situation in the first place.
The Inflation Equation: Creditors vs. Debtors
How can you minimize the chances that an economy gets caught at the zero nominal bound where short-term Treasury bonds and cash are perfect substitutes and conventional open-market operations have no effects? The obvious answer is to have a little bit of inflation in the system: not enough to derange the price mechanism, but enough to elevate nominal interest rates in normal times, so that monetary policy has plenty of elbow room to take the steps it needs to take to create macroeconomic stability when recession threatens. We want "creeping inflation."
How much creeping inflation do we want? We used to think that about 2% per year was enough. But in the past generation major economies have twice gotten themselves stranded on the rocks of the zero nominal bound while pursuing 2% per year inflation targets. First Japan in the 1990s, and now the United States today, have found themselves on the lee shore in the hurricane.
That strongly suggests to me that a 2% per year inflation target is too low. Two macroeconomic disasters in two decades is too many.