Duration Gap in a Rising-Rate Environment
Meridian Retirement holds a $1.17 billion fixed annuity block. Liabilities have a duration of 9.2 years; invested assets of $1.35 billion have a duration of 6.4 years and a book yield of 4.1%. Over six months, the 10-year yield rose 120 basis points. Surplus is $180 million. The investment committee is considering three options: extend asset duration with 30-year corporates, add a receive-fixed interest rate swap overlay, or shorten liabilities through a reinsurance transaction. The CFO is worried about accounting volatility if derivatives are used; the CRO is worried about credit spread widening on long corporates. The board wants to protect the solvency ratio, currently 148%, and avoid a capital raise.
1. Estimate the directional effect of the 120 basis point rate rise on surplus and the solvency ratio, showing the duration logic.
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Using duration only, the asset value change is approximately −$1.35bn × 6.4 × 1.2% = −$103.7m. The liability change is approximately −$1.17bn × 9.2 × 1.2% = −$129.2m. Because liabilities fall more than assets, surplus rises by about $25.5m, from $180m to $205.5m. If the current solvency ratio is 148%, required capital is about $180m ÷ 1.48 = $121.6m; the new ratio is about $205.5m ÷ $121.6m = 169%. This is a directional estimate only: convexity, spread widening, and policyholder behavior could change the result. The key point is that the duration gap has helped in a rising-rate move, but the same gap would hurt if rates fell, so the board should not treat the current gain as a reason to ignore the mismatch.
2. Compare the three options for closing the duration gap, including accounting, credit, and execution risks.
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Extending with 30-year corporates raises asset duration but concentrates credit and liquidity risk at the long end, and spread widening could offset the rate benefit. It is relatively simple operationally and avoids derivative accounting volatility. A receive-fixed swap overlay can extend duration efficiently and is reversible, but it introduces mark-to-market volatility, collateral calls, and hedge-accounting complexity; the CFO's concern is legitimate. A reinsurance transaction shortens liabilities and reduces the block, but it crystallizes a cost, may transfer profitable business, and takes time to execute. On balance, a partial swap overlay combined with selective long-corporate purchases diversifies execution risk, while reinsurance should be evaluated as a capital tool rather than a duration tool. The committee should size any overlay to close only part of the gap, not to eliminate it.
3. Recommend a course of action to the board, with conditions and monitoring.
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Recommend against a single large bet. Approve a phased program: extend asset duration by about 1.0–1.5 years using high-quality long corporates, and use a receive-fixed swap overlay to add a further 1.0–1.5 years, subject to a derivative policy that sets collateral limits and hedge-accounting treatment. Do not target full duration matching immediately, because the current rate move has already improved surplus and chasing the long end could lock in spread risk. Set conditions: maintain a liquidity buffer for collateral calls, limit long-corporate credit exposure by issuer and sector, and model a 100bp rate fall to confirm the solvency ratio stays above the board's risk appetite. Report duration gap, hedge effectiveness, and collateral postings monthly. Reinsurance should remain an option if the block's capital intensity rises, but not as the first response.