Independence, Fiscal Dominance and Financial Stability: Macroprudential Tools, Lender of Last Resort and the 2023 Banking Stress

What you will learn

• How to recognise fiscal dominance in numbers using the debt-dynamics equation.
• The main macroprudential buffers and how they differ from rate policy.
• How lender-of-last-resort support worked in March 2023 and why AT1 bonds were written to zero.

Explanation

Independence and fiscal dominance

Central bank independence means setting rates without government approval and never being ordered to finance the budget. The ECB's independence and the ban on monetary financing are in the EU treaties; the Fed's rests on law and custom, and in 2025 it came under open political pressure in the United States. A government with large debts always prefers lower rates today.

Fiscal dominance is the situation in which public debt is so large that higher rates threaten government solvency, so the central bank is pushed to keep rates low or buy bonds. It is a matter of degree. The key equation for the debt ratio d (debt as a share of GDP) is:

change in d ≈ (r − g) ÷ (1 + g) × d − primary balance

where r is the average nominal interest rate on the debt, g is nominal GDP growth and the primary balance is the budget balance before interest. If r is above g, debt grows by itself unless the government runs a primary surplus. Rate hikes push r up slowly, because debt is refinanced over years. Two warning indicators: interest payments as a share of revenue, and the share of debt maturing within one year.

Macroprudential tools

Macroprudential policy aims at financial stability, not inflation, and works through bank capital and lending standards: the countercyclical capital buffer (CCyB, extra equity held in good times and released in a downturn), systemic risk buffers for specific exposures, and borrower-based measures such as loan-to-value caps. In Germany BaFin set the CCyB at 0.75% of risk-weighted assets and a sectoral buffer on residential mortgages, reduced from 2% to 1% in May 2025; check the current values. Germany has so far relied on buffers rather than binding loan-to-value limits.

Lender of last resort

Walter Bagehot's rule of 1873: in a panic, lend freely, against good collateral, at a penalty rate. March 2023 tested it. Silicon Valley Bank had placed deposits in long-dated bonds; when yields rose, unrealised losses exceeded its equity, uninsured depositors fled within two days, and the bank was closed on 10 March 2023. The Fed created the Bank Term Funding Program, lending for up to one year against government bonds valued at par, not at market price, to break the run. In Switzerland, Credit Suisse was merged into UBS on 19 March 2023 with central bank liquidity support, and roughly CHF 16 billion of its Additional Tier 1 (AT1) bonds were written down to zero while shareholders kept a small payment. AT1 bonds are designed to absorb losses when a bank's viability is in question; investors who treated them as ordinary high-yield bonds learned otherwise.

Worked example

Hypothetical example (all figures invented): debt 130% of GDP, average interest rate 3.0%, revenue 45% of GDP, nominal growth 2.5%, new-issue rate 3.5%. A regional bank holds €100 million of held-to-maturity bonds with duration 6.0 and has €12 million of equity.

Step 1 – interest burden: 3.0% × 130% = 3.9% of GDP; 3.9 ÷ 45 = 8.7% of revenue. Above roughly 10% analysts talk of fiscal pressure; the threshold is a convention.

Step 2 – once all debt is refinanced at 3.5%: (3.5% − 2.5%) ÷ 1.025 × 130% ≈ 1.27% of GDP primary surplus just to hold the ratio at 130%. Each extra 100 basis points, once passed through, adds about 1.27 points: this is where the pressure for lower rates comes from.

Step 3 – the bank: yields rise 300 basis points. Mark-to-market loss ≈ 6.0 × 3.0% × €100 million = €18 million, more than the €12 million of equity. Economically insolvent, in accounting terms fine as long as it never sells.

Step 4 – the run: if depositors withdraw €30 million and bonds must be sold at an 18% loss, the loss is crystallised. A lender of last resort accepting the bonds at par lets the bank borrow €30 million without selling, as in 2023. Whether that is a liquidity or a hidden solvency rescue depends on whether yields fall before maturity.

Common mistake

Practice activity

On paper: debt 100% of GDP, revenue 40% of GDP, average interest rate 4.0%, nominal growth 3.0%. (a) Interest burden as a share of GDP and of revenue. (b) Primary balance that stabilises the debt ratio. (c) The average rate eventually reaches 5.0%; new required primary balance. (d) A bank holds €50 million of bonds with duration 4.0 and €5 million of equity; yields rise 200 basis points. Does the loss exceed equity?

Key takeaways

• Fiscal dominance builds through the r − g gap and the maturity of the debt; watch interest as a share of revenue.
• Macroprudential buffers such as the CCyB target bank resilience and can be released in stress, separate from rate policy.
• Lender-of-last-resort support in 2023 stopped runs by lending against bonds at par; it did not protect shareholders or AT1 holders, so check your instrument's place in the loss hierarchy.

Next step

In the final lesson we assemble everything into a meeting preparation checklist and a post-meeting review template you can use for every central bank decision.