Can Too Little Government Debt Be a Problem?

Introduction

Public debt is usually discussed as something governments should reduce. Lower debt can mean smaller interest bills, greater fiscal flexibility and less vulnerability to future crises. From that perspective, the idea that a country could have too little government debt sounds almost absurd. Yet financial markets do not view sovereign bonds only as liabilities of the state. Banks hold them as liquid assets, pension funds use them to match long-term liabilities, dealers finance them in repo markets and central banks use them in monetary operations. In major economies, government securities often sit near the top of the collateral hierarchy because they are liquid, standardized and widely accepted.

A shrinking supply of high-quality sovereign bonds can therefore create problems even when the government’s fiscal position is improving. The paradox is simple: what is desirable for the public balance sheet is not always ideal for the financial system that depends on government securities.

Why Markets Need Safe Assets

Modern finance requires assets that institutions can trust, price quickly and convert into cash with relatively little friction. Government bonds from highly credible issuers often perform that role better than most private securities. Banks need liquid assets they can sell or pledge during stress. Money-market funds and institutional investors need short-term instruments for cash management. Derivatives markets require collateral. Repo markets depend heavily on securities that lenders are willing to accept with low haircuts.

A well-functioning sovereign bond market therefore provides more than funding for the government. It creates a pool of standardized assets that can support transactions throughout the private financial system.

When that pool becomes too small, institutions do not simply stop needing safe collateral. They begin competing more intensely for what remains.

Less Debt Can Mean Less Collateral

Reducing government debt can strengthen public finances while simultaneously reducing the supply of securities used as collateral, liquidity reserves and pricing benchmarks but that does not mean governments should borrow unnecessarily.

It means the financial system can attach value to government debt that goes beyond the interest paid to investors.

What Happens When Safe Bonds Become Scarce?

Scarcity can appear in several ways. Certain government securities may trade at unusually rich prices because many institutions need them for settlement or collateral. Repo rates can move sharply for specific bonds, while investors become willing to accept lower yields simply because the securities are useful. Benchmark markets can also become less liquid if issuance falls too far. Fewer bonds outstanding may mean less trading, weaker price discovery and less reliable reference rates for corporate bonds and other financial instruments.

The issue is not necessarily the total quantity of public debt. Distribution matters. A country can have substantial debt outstanding while the most desirable securities are locked inside central-bank portfolios, foreign reserves or long-term institutional holdings and therefore circulate only rarely.

For financial institutions, an asset that exists but cannot easily be borrowed or traded may be of limited practical use.

Why Private Assets Cannot Fully Replace Government Bonds

Corporate bonds, covered bonds and other high-quality securities can provide alternatives, but they are not perfect substitutes and private securities carry credit risk linked to individual firms or sectors. Their markets are usually smaller, liquidity can deteriorate more rapidly during stress and pricing may become less reliable precisely when collateral is needed most.

Government securities benefit from deeper markets, broader ownership and a special position within regulatory and central-bank frameworks. That combination makes them unusually useful during periods when confidence in private assets is declining.

Substituting private collateral for sovereign securities can therefore work under normal conditions while becoming more difficult during a crisis.

The Benchmark Problem

A government bond market also provides a reference curve for the rest of the economy and corporate issuers are commonly priced relative to sovereign yields. Banks use government curves when valuing loans and securities. Derivatives markets rely on benchmark rates, while investors compare risk premiums across different assets. If the supply of benchmark government bonds becomes too limited, price discovery can become less efficient. Certain maturities may trade infrequently, making it harder to determine the underlying risk-free or low-risk rate against which other securities are measured.

For a major financial centre, maintaining a functioning sovereign curve can therefore have value even when the government does not urgently require financing.

Singapore is a useful example of this logic. Government securities can be issued partly because markets benefit from having them, not simply because the state needs money for current expenditure.

Could a Government Deliberately Issue Debt for Market Reasons?

In principle, yes. A government may continue issuing securities to maintain benchmark markets, provide safe assets or support monetary operations even when fiscal conditions are strong. The proceeds do not necessarily need to finance ordinary expenditure in the way deficit borrowing does. This does not create free money. Interest must still be paid and the liabilities remain on the public balance sheet. Issuing debt purely because markets want collateral therefore involves a trade-off between financial-market benefits and fiscal costs.

The important point is that debt issuance can have a market-structure objective as well as a budgetary objective and thatis very different from claiming that more debt is always beneficial.

The Ideal Supply Is Not Zero

From a purely fiscal perspective, eliminating government debt may sound attractive and from a financial-market perspective, zero issuance could remove benchmark securities, reduce available collateral and weaken an important source of safe assets.

The optimal amount of government debt is therefore not determined by financial markets alone, but the market function of sovereign bonds cannot be ignored.

Why This Matters for Investors

This idea changes how investors should interpret falling government debt. A declining debt ratio may improve sovereign creditworthiness, but it can also increase scarcity premiums in certain securities. Yields may fall not only because investors believe the government is safer, but because the bonds themselves are becoming more valuable as collateral or benchmark instruments.

The reverse can also happen. Heavy government issuance increases the supply of safe assets, potentially improving collateral availability while putting upward pressure on yields through greater bond supply and sovereign debt therefore creates two competing effects: fiscal risk increases when borrowing becomes excessive, while financial-market usefulness can increase when high-quality securities are available in sufficient quantity.

Understanding both sides provides a more complete view of government bond markets.

Conclusion

Too much government debt can create serious economic and fiscal risks. But reducing sovereign debt to zero would not automatically produce an ideal financial system. High-quality government bonds provide collateral, liquidity, benchmark pricing and safe assets used throughout modern finance. A sufficiently small supply can create scarcity and weaken market functioning even when the government’s own finances look exceptionally strong.

Government debt is not only a burden to be serviced. In the right form, it is also infrastructure the financial system uses every day.