Board of Governors of the Federal Reserve System. This study was completed while the author was at the Federal Reserve Bank of Philadelphia. Helpful comments on this paper by Ira Kaminow and Anthony Santomero are gratefully acknowledged. The author also benefitted from numerous discussions of the issues addressed with other members of the Philadelphia Federal Reserve Bank's Research Department. Contents of the paper are the sole responsibility of the author and do not necessarily reflect the views of the Board of Governors or Federal Reserve Bank of Philadelphia.