Contents include: Robust Monetary Policy Rules with Unknown Natural Rates, Ahtnasios Orphanides (Board of Governors, Federal Reserve) and John C. Williams (Federal Reserve Bank of San Francisco) The Role of Models and Probabilities in the Monetary Policy Process Christopher Sims (Princeton) Current Account Deficits in the Euro Area: The End of the Feldstein Horioka Puzzle? Olivier Blanchard (MIT) and Francesco Giavazzi (Bocconi University) P roductivity Growth and the New Economy William D. Nordhaus (Yale)