THE MARKET FOR U.S. Treasury notes and bonds is widely considered as one of
the most active and liquid markets in the world. The recent revelation that
Salomon Brothers accumulated a large position in the two-year notes issued
in the May 1991 auction and allegedly manipulated the price of this issue has
led many investors to question the price efficiency in this market. For
instance, one of the lead articles in the Wall Street Journal dated August 19,
1991 (p. Al) reports that "Collusion and price fixing in the $2.3 trillion
Treasury securities market have been routine for more than a decade,
according to traders and top Wall Street executives."
Such assertions have led to calls for changes in the auction rules and
tighter regulation of the market for Treasury securities and evidently, such
measures are being contemplated by the Treasury. For instance, the same
issue of the Wall Street Journal (p. A5) reports that the "Treasury is
considering significant changes in how it sells government debt," and the
Wall Street Journal dated August 26, 1991 (p. Al) quotes the Fed Vice
Chairman David Mullins as saying "We need to examine mechanisms to
improve the efficiency of the market, (and) reduce the cost of Treasury
finance...'" While it is possible that technicalities such as position limits
were violated in Treasury auctions, models of rational economic behavior
predict that collusion cannot be sustained in a market with as many partici-
pants as in the Treasury auctions. It is therefore important to investigate
*University of California, Los Angeles and University of Illinois at Urbana-Champaign. I
would like to thank Jim Brandon, Michael Brennan, Brad Cornell, Darrell Duffie, Francis
Longstaff, Jill Ousley, Jerome Powell, Gary Rasmussen, Rene Stulz, Suresh Sundaresan, Sheri-
dan Titman, Bruce Tuckman, and an anonymous referee for helpful comments and/or discus-
sions. Phong Chan, Karen Gess, and Ravi Jain provided excellent research assistance. This
research was partially supported by a UCLA Faculty Career Development Award and a research
grant from the UCLA Academic Senate. I am solely responsible for any error in this paper.