Central Bank Balance Sheet Risks
The Duration Mismatch
QE creates a structural duration mismatch:
- Assets: Long-duration bonds (bought at low rates)
- Liabilities: Short-term reserves (paying current short rates)
When rates rise: negative carry AND mark-to-market losses simultaneously.
“After the central bank has bought a lot of debt and interest rates have risen so debt prices have fallen and the central bank’s short-term costs of funds are greater than the returns on the debt they bought, central banks have losses that are so big that they lead the central banks to have negative net worths. That is another red flag.” — a-00096
Current Fed situation (post-2022): The Fed has experienced this exact dynamic — negative equity from QE legacy portfolio + rising rate funding costs. This is a yellow flag, not yet crisis-level.
The Death Spiral
“When that happens, that is notable but not a big red flag until the central bank has a significant negative net worth and is forced to print more money to cover the negative cash flow that it experiences due to less money coming in on its assets than has to go out to service its debt liabilities. That is a big red flag because it signals the central bank’s death spiral.” — a-00095
Death spiral sequence:
- CB holds long bonds; rates rise
- CB negative carry (funding costs > asset income)
- CB operating losses force money printing to cover
- More printing → more inflation
- Rates rise further → more losses → more printing
The critical threshold: when CB losses must be monetized (CB cannot get capital from Treasury without political controversy). At that point, the spiral is visible to markets.
CB Independence as Firewall
“In order to build confidence in a new currency, countries in inflationary deleveragings need to stop monetizing debt. As long as the government can force the central bank to print to cover its liabilities, there is a risk that the new currency will be debased.” — a-00205
CB independence prevents fiscal dominance: government cannot force CB to print unlimited amounts. When independence is eroded (political pressure, legislative changes), the inflation constraint disappears.
Historical pattern: CB independence erodes in late-stage Big Debt Cycles when governments face severe fiscal stress. The pressure is always to finance deficits through money creation rather than accept the political cost of austerity.
“The Fed can’t openly say that it will go along with this plan (though deals between the Fed keeping interest rates low while the government was cutting the deficit have been made in the past).” — a-00112 (context)
Monitoring the Fed (2025)
| Metric | Status |
|---|---|
| Net worth | Negative (estimated -$100-200B) |
| Annual losses | ~$100-150B/year |
| Duration mismatch | Large (QE portfolio at low rates) |
| Death spiral risk | Low (losses funded by deferred remittances, not printing) |
Current mitigant: The Fed covers losses by reducing remittances to Treasury (deferred asset accounting), not by creating new reserves. This is NOT the same as printing. Risk becomes real if losses become large enough to require actual reserve creation.
Stage 5: CB Becomes Sovereign Lender of Last Resort
“Ultimately, the government can’t escape the fact that it needs to find much more financing for its spending priorities. But at this stage, it typically experiences financing rates higher than it can afford—often because of the mechanical selling of the currency and debt. Needing financing, the government turns to the central bank, which essentially becomes its lender of last resort.” — a-00251
Stage 5 marks the moment of fiscal dominance: when private market financing becomes unaffordable (spreads widening due to creditor fear), the CB must monetize or the government defaults. From this point, fiscal policy drives monetary policy regardless of formal CB independence. The CB’s balance sheet risk escalates because monetizing government debt ties its solvency to the government’s fiscal trajectory. — a-00251