In the 2-1/2 years between March, 1996 and September, 1998 the civilian unemployment rate in the United States dropped a full percentage point, the 12-month CPI inflation rate fell nearly 1-1/2 percentage points, a major crisis developed in emerging economies, and commodity prices collapsed....

This paper explores Knightian model uncertainty about dynamic misspecification as a possible explanation of the considerable difference between estimated interest rate rules and optimal feedback descriptions of monetary policy. In the literature on robust control, Knightian uncertainty about a...

We examine learning, model misspecification, and robust policy responses to misspecification in a quasi-real-time environment. The laboratory for the analysis is the Sargent (1999) explanation for the origins of inflation in the 1970's and the subsequent disinflation. Three robust policy rules...

In the late 1960s and into the 1970s, the United States experienced a burst of inflation the origins of which seemed hard to uncover. This paper advances the idea that the Fed simply got the model wrong. We assume that the true model of the economy is a variant of the standard New Keynesian...

In recent years, the learnability of rational expectations equilibria (REE) and determinacy of economic structures have rightfully joined the usual performance criteria among the sought after goals of policy design. And while some contributions to the literature (for example Bullard and Mitra...

In his monograph The Conquest of American Inflation, Sargent (1999) points out the perils of econometric policy evaluation of the Theil-Tinbergen tradition wherein one estimates a reduced form econometric model of the economy and subjects it to control. If the model is misspecified, as is...