Why reserve movements matter
A policy liability represents the value, on a specified valuation basis, of obligations still attached to a contract or portfolio. Reported surplus depends on that liability as well as on the assets available to meet it. Consequently, a change in the reserve can affect reported surplus even when no cash changes hands at the date of valuation.
This distinction is important when explaining a period’s result. Some surplus variation comes from experience: for example, actual claims differ from expected claims. Another part may arise because the liability is recalculated using different assumptions. The two effects can occur together, but they are not the same source of gain or loss.
The balance-sheet reconciliation
For any two valuation dates, the change in surplus is the change in assets minus the change in liabilities. This identity holds whether the reserve movement is expected, caused by experience, or caused by a new valuation basis.
The identity gives a direct way to check a surplus reconciliation. Asset growth, including premiums and investment income and net of benefits and expenses, contributes positively to the change in surplus. An increase in the closing liability offsets that contribution; a decrease adds to it.
Worked Example: Reconciling Assets, Reserve Growth, and Surplus
A hypothetical participating portfolio has opening assets of $100,000 and an opening reserve of $95,000. During the year, assets earn 4% interest, premiums of $10,000 are received, claims of $5,000 are paid, and expenses of $2,000 are paid. The closing reserve is $99,000. For mortality, assume 20 identical policies with independent one-year death probabilities of 0.05 under the valuation basis; the death-count model is Binomial(20, 0.05), and one death actually occurs, producing the stated $5,000 claim. Treat the stated reserve amounts as valuation results on a 4% interest basis. Find the change in reported surplus and reconcile it.
Method. First roll the assets forward from the specified interest and cash flows. Then compare opening and closing surplus using the balance-sheet identity.
Investment income is \(0.04(100{,}000)=\$4{,}000\). Therefore closing assets are
Opening surplus is \(S_0=100{,}000-95{,}000=\$5{,}000\). Closing surplus is \(S_1=107{,}000-99{,}000=\$8{,}000\), so the surplus increase is \(\$3{,}000\).
As a check, assets increased by \(\$7{,}000\), while the reserve increased by \(\$4{,}000\). Thus
The method avoids treating the reserve increase as the whole period result. The \(\$4{,}000\) strengthening offsets part of the \(\$7{,}000\) increase in assets; it does not erase that asset movement.
Experience gains and valuation-basis effects
An experience gain or loss compares actual experience with the experience expected on a specified basis. To make that comparison meaningful, hold the valuation basis and the other relevant conditions fixed. For example, with claims as the only differing item, fewer actual claims than expected leave more assets than the expected outcome and create an experience gain.
A valuation-basis effect is different. It compares liability values calculated for the same contracts at the same date using different assumptions. If assets are held fixed, changing a reserve from \(V^{\text{old}}\) to \(V^{\text{new}}\) changes surplus by \(V^{\text{old}}-V^{\text{new}}\). A strengthened liability therefore reduces reported surplus; a reduced liability increases it. That reported change is a remeasurement effect, not evidence that actual claims, investment returns, or expenses were better or worse than expected.
This result follows by subtracting the two surplus measures while holding the asset amount \(A\) unchanged. The assets cancel, leaving only the difference between the old and new liabilities. It is a comparison at one date, not a formula for the complete change in surplus over a period.
Worked Example: Separating a Mortality Gain from a Reserve Strengthening
A hypothetical group has 100 policies, each with a $10,000 death benefit. Under the old valuation basis, one-year mortality is 0.02 independently for each policy, so deaths follow Binomial(100, 0.02) and expected deaths are 2. One death actually occurs. Expected closing assets before the claim difference are $290,000; all other cash flows are the same in the expected and actual comparisons. The actual assets are therefore higher by the difference between two expected claims and one actual claim. At closing, the old-basis reserve is $230,000. A revaluation uses 4% interest and mortality 0.015 per policy, independently, instead of the old 5% interest and 0.02 mortality; the resulting new-basis reserve is $238,000. Find the actual surplus on each basis and separate the two effects.
Method. First compare actual claims with expected claims under the old basis. Then revalue the closing liability while holding actual assets fixed.
Expected claims are \(2(\$10{,}000)=\$20{,}000\), while actual claims are \(1(\$10{,}000)=\$10{,}000\). The actual claim outgo is \(\$10{,}000\) lower, so actual closing assets are \(290{,}000+10{,}000=\$300{,}000\).
On the old basis, expected closing surplus is \(290{,}000-230{,}000=\$60{,}000\), and actual closing surplus is \(300{,}000-230{,}000=\$70{,}000\). The difference of \(\$10{,}000\) is the mortality experience gain.
On the new basis, actual closing surplus is \(300{,}000-238{,}000=\$62{,}000\). The basis change has reduced surplus by \(238{,}000-230{,}000=\$8{,}000\). Relative to the expected closing surplus on the old basis, the net difference is \(\$10{,}000-\$8{,}000=\$2{,}000\). Thus the experience gain is positive, but the assumption change offsets most of it. The new reserve is stipulated as the result of revaluation; it is not calculated from the one-year death-count distribution alone.
A release is not automatically a gain of the same amount
A reserve release is a reduction in the liability, but a policy termination may also trigger a payment. The effect on surplus is the liability released less the related reduction in assets, together with any other associated cash flows. Counting the released reserve as profit while ignoring the payment overstates the result.
Worked Example: A Surrender Payment and the Associated Reserve Release
A hypothetical portfolio has five policies, each with assets and reserve of $10,000, so opening assets and the opening reserve are both $50,000. During the period, one policy surrenders and receives $9,000. There is no interest, expense, or death claim during the period; mortality is zero for this deterministic one-period calculation, and one surrender is specified. Each of the four remaining policies continues to have a $10,000 closing reserve. Calculate closing surplus and identify the surrender’s net effect.
Method. Reduce assets by the surrender payment and reduce the liability by the surrendered policy’s reserve. Compare the two changes.
Closing assets are \(50{,}000-9{,}000=\$41{,}000\). The closing reserve is \(4(10{,}000)=\$40{,}000\). Hence closing surplus is \(41{,}000-40{,}000=\$1{,}000\), compared with opening surplus of zero.
The reserve release is \(\$10{,}000\), but the surrender payment reduces assets by \(\$9{,}000\). Their net contribution to surplus is \(\$10{,}000-\$9{,}000=\$1{,}000\), matching the closing balance-sheet calculation.
Common mistake. Counting the \(\$10{,}000\) reserve release as the gain gives the wrong answer. The correction is to include the \(\$9{,}000\) payment: the net gain is only \(\$1{,}000\).
How to present a reserve-related surplus explanation
A clear reconciliation separates the components rather than combining them into a single unexplained number. State the opening and closing assets and liabilities, identify the reserve basis used at each point, and explain whether a difference reflects actual experience or remeasurement. If both occur, quantify them separately and then show their combined effect.
Specify the period, the portfolio, and the valuation basis. For an experience comparison, compare actual with expected experience on the same basis.
Include income and premiums, then subtract benefits and expenses, using the timing and amounts stated in the problem.
Record the opening and closing reserves, and identify any change caused solely by a revised valuation basis.
Apply \(\Delta S=\Delta A-\Delta V\), check the closing balance sheet, and label each component as experience or remeasurement.
The central exam trap is to confuse a change in reported surplus with a change in underlying experience. A reserve strengthening can reduce current reported surplus even if actual experience was favorable. Conversely, a reserve release can increase reported surplus without demonstrating favorable experience. Always state which comparison is being made.
Check Your Understanding
For each problem, calculate the requested surplus effect and distinguish reserve movements from cash-flow or experience effects where relevant.
- A portfolio starts with assets of $80,000 and reserves of $76,000. Over the year, assets earn 3% on opening assets, receive $5,000 of premiums, pay $2,000 of benefits, and pay $1,000 of expenses. The closing reserve is $78,500. Find the change in surplus. (Answer: increase of $1,900.)
- At a valuation date, assets are $150,000. The reserve is revised from $142,000 to $146,000 with assets unchanged. State the change in reported surplus caused by the revaluation. (Answer: decrease of $4,000.)
- A hypothetical group has 50 policies with a $4,000 death benefit each. Independent mortality probabilities are 0.04, giving a Binomial(50, 0.04) death count with expected value 2; one death occurs instead of the expected two. The reserve is then strengthened by $6,000, with all other items held fixed. Find the combined difference from the expected outcome on the old basis. (Answer: decrease of $2,000.)
- Eight policies each have assets and reserves of $7,500 at the start. Two surrender and each receives $6,800. Interest is 0%, there are no other cash flows or deaths, and each of the six remaining policies retains a $7,500 reserve. Find closing surplus. (Answer: $1,400.)
- For 30 hypothetical policies with a $20,000 death benefit each, independent mortality probabilities of 0.05 give expected deaths of 1.5. One death occurs, so actual claims are $10,000 below expected claims. Expected closing assets are $520,000. The old-basis reserve is $500,000 and the revised-basis reserve is $506,000; the revaluation uses the stated revised assumptions with all assets held fixed. Find the actual closing surplus on the revised basis and its difference from expected closing surplus on the old basis. (Answer: actual revised-basis surplus $24,000; net increase of $4,000.)