Contents: Preface -- Part I: Imperfect information, responses to shocks, and credibility issues -- 1. Introduction, Part 1 -- 2. A basic model and some early results -- 3. The strategy of monetary policy: Targets, instruments and information variables -- 4. A variable price level, supply shocks...

The recent crisis in the United States has often been associated with substantial amounts of policy uncertainty. In this paper we ask how uncertainty about fiscal policy affects the impact of fiscal policy changes on the economy when the government tries to counteract a deep recession. The...