Money and the Public Debt: Treasury Market Liquidity as a Legal Phenomenon

Abstract

The market for U.S. government debt (Treasuries) forms the bedrock of the global financial system. The ability of investors to sell Treasuries quickly, cheaply, and at scale has led to an assumption, in many places enshrined in law, that Treasuries are nearly equivalent to cash. Yet in recent years Treasury market liquidity has evaporated on several occasions and, in 2020, the market’s near collapse led to the most aggressive central bank intervention in history.

This Article pieces together what went wrong and offers a new account of the relationship between money issue and debt issue as mechanisms of public finance. It argues that a high degree of convertibility between Treasuries and cash generally requires intermediaries that can augment the money supply, absorbing sales by expanding their balance sheets on both sides. The historical depth of the Treasury market was in large part the result of a concerted effort by policymakers to nurture and support such balance sheet capacity at a collection of nonbank broker-dealers. In 2008, the ability of theseintermediaries to augment the money supply became impaired as investors lost confidence in their money-like liabilities (known as repos). Subsequent changes to market structure pushed substantial Treasury dealing further beyond the bank regulatory perimeter, leaving public finance increasingly dependent on high-frequency traders and hedge funds—“shadow dealers.” The near money issued by these intermediaries proved highly unstable in 2020. Policy makers are now focused on reforming Treasury market structure so that Treasuries remain the world’s most liquid asset class. Successful reform likely requires a legal framework that, among other things, supports elastic intermediation capacity through balance sheets that can expand and contract as needed to meet market needs.