Universal Life Account Value Projection and Asset-Liability Duration Gap
Project a UL account value roll-forward under a credited-rate scenario, then quantify surplus sensitivity to a parallel rate shock using duration and convexity.
Background
Beacon Life issued a universal life (UL) policy with an initial account value of 3,000, a face amount of = \text{face} - AV1,000 of NAAR times 12 (a simplified annualized approximation of a monthly COI structure), then a flat $60 policy expense charge, with interest credited at the end of the year on the resulting balance at a scenario-dependent credited rate.
Five-year projection under the base credited-rate scenario
Beacon's ALM team projects the following credited rates for years 1–5, reflecting a gently declining-then-recovering new-money rate environment: .
| Yr | Beg. AV | Net premium (after 5% load) | COI | Policy exp. | Credited interest | End AV |
|---|---|---|---|---|---|---|
| 1 | 10,000.00 | 2,850.00 | 4.32 | 60.00 | 447.50 | 13,233.18 |
| 2 | 13,233.18 | 2,850.00 | 4.16 | 60.00 | 480.57 | 16,499.58 |
| 3 | 16,499.58 | 2,850.00 | 4.01 | 60.00 | 540.00 | 19,825.57 |
| 4 | 19,825.57 | 2,850.00 | 3.85 | 60.00 | 723.58 | 23,335.30 |
| 5 | 23,335.30 | 2,850.00 | 3.68 | 60.00 | 783.65 | 26,905.27 |
The COI charge shrinks slightly each year (from 3.68) simply because the account value is growing while the face amount is fixed, so NAAR shrinks and with it the dollar COI, even though the rate per $1,000 of NAAR is held flat in this projection — a reminder that UL charges depend on the interaction of a contractual rate and a policy-specific, dynamically-changing base (NAAR), not the rate alone.
Asset-liability duration mismatch
Beacon's asset segment backing this UL block has market value D_A = 6.2C_A = 601,150,000, duration , convexity . Under a hypothetical parallel downward shock of 100 basis points (), the standard duration-convexity approximation for the change in value of an asset or liability with value , duration and convexity is
Applying this:
Starting surplus (assets minus liabilities) is 1{,}250{,}000-1{,}150{,}000=\100{,}000100{,}000+81{,}250-53{,}762.50 = $127{,}487.5027,487.50** — because Beacon's assets have longer duration than its liabilities (a positive duration gap, ), a rate decrease raises asset values by more than liability values, helping surplus. The leverage-adjusted duration of surplus itself, defined as
is far larger than either or individually — a direct consequence of leverage (small surplus base relative to assets/liabilities), which is the reason insurers with even modest duration mismatches can see outsized percentage swings in surplus from parallel rate moves.
The risk this creates
Although a rate decrease helped surplus in this scenario, the same duration gap means a rate increase would hurt surplus by a similar order of magnitude — Beacon is exposed to interest-rate risk in both directions depending on the sign of the shock, and management must decide whether to accept this asymmetric-cost/asymmetric-benefit profile, hedge it (e.g., pay-fixed swaps or duration-extending bond purchases to shrink the gap), or hold additional capital against it. UL blocks are particularly exposed to this because policyholders can react to rate moves via lapses or additional premium ("disintermediation risk"), which was not modeled in the simple projection above but is a standard qualitative concern examiners expect candidates to raise.
Your task
Using the figures above as given, answer the following. Where asked to extend the analysis (e.g., a different shock size or COI/credited-rate scenario), apply the same formulas shown here.
Part A — Multiple choice (6 × 1 point)
In year 4 of the projection, the dollar COI charge (3.85) is lower than in year 1 (4.32) even though the COI rate per $1,000 of NAAR is unchanged. Why?
Beacon's assets have duration 6.2 versus liabilities at 4.5 (a positive duration gap). Under a parallel increase in rates, what would you expect for surplus, all else equal?
The leverage-adjusted duration of surplus is calculated as 25.75, far exceeding either D_A=6.2 or D_L=4.5. What causes this magnification?
If Beacon's policyholder stops paying premiums after year 3 (a common lapse-adjacent behavior), which of the following is the most direct mechanical effect on the account value projection from year 4 onward?
Which risk, not explicitly modeled in the deterministic account-value projection above, is most commonly cited as a key incremental exposure for UL blocks under rising interest-rate scenarios?
The convexity term contributes 0.5 \times 60 \times (0.0001) \times 1{,}250{,}000 = \3{,}750$ to the asset value change. What is the general effect of positive convexity on a duration-based valuation estimate?
Part B — Written response
Beacon's ALM committee is debating whether to close the 1.7-year duration gap (D_A=6.2 vs D_L=4.5) by selling long bonds and buying shorter ones, versus leaving it open and holding additional economic capital. Discuss the tradeoffs, referencing the surplus figures in this case.
Recompute (showing your work) the year-1 ending account value if the credited rate for year 1 were instead 2.0% rather than 3.5%, holding all other year-1 assumptions (premium, COI, expense charge) fixed. Comment on the sensitivity of the account value to the credited-rate assumption.