The IMF Working Papers series is designed to make IMF staff research available to a wide audience. Almost 300 Working Papers are released each year, covering a wide range of theoretical and analytical topics, including balance of payments, monetary and fiscal issues, global liquidity, and national and international economic developments.
This paper proposes a new method of estimating the Taylor rule with a time-varying implicit inflation target and a time-varying natural rate of interest. The inflation target and the natural rate are modeled as random walks and are estimated using maximum likelihood and the Kalman filter. I apply this method to U.S. monetary policy over the past 25 years and find considerable time variation in the implicit target, confirming hypotheses about "opportunistic disinflation" and the recent "deflation scare."