The purpose of this paper is to explore the reasons underlying the variable and sometimes very large differentials between United States Treasury bill rates and private sector U.S. money market rates of comparable maturity

Observed differentials among yield series for different types of long-term instruments -- U.S. government bonds, municipal bonds, corporate bonds and residential mortgages -- vary considerably over time

This paper answers questions raised about our use of the Wall Street Journal in an earlier paper in which we estimated the effect of changes in the federal funds rate target -- the Federal Reserve's policy instrument -- on market interest rates in the 1970s. In that paper we found that changes...