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IAI Actuarial Core Principles · Business Management

Issues and challenges in each main practice area: formula sheet

Full chapter guide

Key formulas

Persistency rate
Persistency = Policies in force at end of period ÷ Policies in force at start of period
Define the cohort and period clearly. Insurers often track persistency by policy year (for example 13th month, 25th month).
Lapse rate
Lapse rate = Policies lapsed in period ÷ Policies exposed at start of period
For a single period with no other exits, lapse rate = 1 − persistency rate. Deaths and maturities also remove policies, so exclude them or adjust.
Profit margin on premium
Profit margin = Present value of profits ÷ Present value of premiums
Both are discounted at the same rate. Used to compare product designs under different assumptions.
Value of a guarantee (intrinsic)
Intrinsic value at exercise = max(Guaranteed benefit − Market-based benefit, 0)
This ignores time value. The full option cost includes time value and needs a stochastic or option-pricing model.
Solvency position
Excess of assets over liabilities = Available capital − Required capital
Insurer is solvent on this test if the result is not negative. Use the regulator's valuation basis, not your own.
Ultimate claims
Ultimate claims = Paid claims + Case reserves + IBNR
IBNR here includes both claims not yet reported and, in many usages, further development on reported claims (IBNER). State which you mean.
Claims ratio (loss ratio)
Claims ratio = Incurred claims ÷ Earned premium
Use earned, not written, premium.
Combined ratio
Combined ratio = Claims ratio + Expense ratio
Above 100% means an underwriting loss before investment income.
Excess of loss recovery
Recovery = min(max(X − R, 0), L)
X is the loss, R the retention and L the limit of the layer.
Quota share recovery
Reinsurer's claim share = q × X
q is the share ceded. Premium is shared in the same proportion, normally with a ceding commission.
Claims inflation effect
Future cost = Current cost × (1 + i)^n
i is the annual claims inflation rate and n the number of years.
Incurred claims ratio
Incurred claims ratio = Incurred claims ÷ Earned premium
A key monitoring measure. Use incurred claims, not only paid claims, and earned premium, not written premium.
Gross premium (expected-cost approach)
Gross premium = (Expected claims cost + Expenses + Profit and contingency loading) per policy, with each loading allowed for explicitly
A simple structure for explaining pricing. Always list the assumptions behind each part.
Claim cost per policy
Expected claim cost = Claim frequency × Average claim size
Useful to separate the effect of utilisation from the effect of medical inflation.
Effect of cost-sharing on insurer payment
Insurer payment = (Claim − Deductible) × (1 − Co-payment %), if Claim > Deductible, otherwise 0
Applies when the deductible is applied first and the co-payment is a percentage of the remaining amount. Check the policy order in the question.
Compound cost growth
Future cost = Current cost × (1 + i)^n
Use for projecting claim costs under a constant annual medical inflation rate i over n years.
Present value of a liability
PV = Σ B(t) × v(t), where v(t) = 1 ÷ (1 + i)^t
B(t) is the expected benefit payment at time t. A higher i gives a lower PV.
Funding level
Funding level = Assets ÷ Value of liabilities
Below 100% means a deficit on the chosen basis. The result depends on the basis used.
Surplus or deficit
Surplus (deficit) = Assets − Liabilities
A negative answer is a deficit. Always state the valuation basis.
Final salary DB benefit (typical form)
Annual pension = accrual rate × years of service × final salary
For example, 1/60 × 30 × final salary. Scheme rules decide the exact formula.
DC fund at retirement (level contribution at end of each year)
Fund = C × s(n at i) = C × ((1 + i)^n − 1) ÷ i
Assumes a constant return i and a fixed contribution C. Real returns vary, which is why DC members bear investment risk.
Present value of liabilities
PV = Σ Cₜ ÷ (1 + i)ᵗ
Cₜ is the liability cash flow at time t and i is the valuation rate. A lower i gives a higher PV, and the effect is larger for longer liabilities.
Surplus
Surplus = Value of assets − Value of liabilities
Both sides must be valued on a consistent basis. ALM aims to keep surplus stable when conditions change.
Macaulay duration
D = Σ t × Cₜ ÷ (1 + i)ᵗ ÷ PV
The weighted average term of the cash flows, with weights equal to their present values.
Modified duration (approximate price change)
ΔPV ≈ −D_mod × PV × Δi, where D_mod = D ÷ (1 + i)
Valid for small changes in yield. For large changes, convexity matters.
Redington immunisation conditions
(1) PV assets = PV liabilities; (2) Duration of assets = Duration of liabilities; (3) Convexity of assets > convexity of liabilities
Protects against small parallel shifts in the yield curve only. It needs regular rebalancing.
Solvency ratio
Solvency ratio = Available capital ÷ Required capital
A ratio of 1 (100%) means capital equals the requirement. Regulators set the minimum level; check the current IRDAI rule.
Surplus over requirement
Excess capital = Available capital − Required capital
Positive means the firm meets the requirement. Available capital is assets less liabilities, after any admissibility rules.
Value at Risk (VaR)
P(Loss > VaR) = 1 − α
α is the confidence level, such as 99.5%, over a stated time horizon. VaR is the loss threshold, not the average loss beyond it.
Tail VaR (expected shortfall)
TVaR(α) = E[Loss | Loss ≥ VaR(α)]
Average loss in the worst cases. For continuous losses it is at least as large as VaR at the same level.
Economic capital (loss-based view)
Economic capital = VaR(α) − Expected loss
One common definition: capital covers unexpected loss, while expected loss is covered by pricing and reserves. State the definition you use.
Risk response options
Avoid | Reduce | Transfer | Accept
Choose by comparing the risk with appetite and the cost of the response.

Quick revision

  • Use a fixed pattern for each issue: challenge, cause, effect, action.
  • Life: long-term guarantees, persistency, mis-selling risk, interest rate risk and customer outcomes.
  • General insurance: claims uncertainty, reserving, pricing cycles, catastrophe exposure and reinsurance.
  • Health: medical cost inflation, fraud, moral hazard, adverse selection and limited reliable data.
  • Pensions: longevity, funding shortfalls, sponsor strength, investment risk and clear member communication.
  • ALM: mismatch of asset and liability cash flows, duration, liquidity and interest rate movement.
  • ERM: identify, measure, manage and report risks, and hold enough capital for them.
  • Capital issues include cost of capital, regulatory requirements and the trade-off between safety and returns.
  • Emerging areas bring new data, new models and limited history, so state assumptions and uncertainty clearly.
  • Always consider stakeholders: customers, regulator, shareholders, employees and the public.
  • Link every recommendation to the specific case facts, not general statements.
  • Tie in professionalism: act with integrity, communicate clearly and be open about limits of your work.

Common mistakes

  • Listing risks without linking them to the product in the question. Fix: Start from the product features. For example, say a guaranteed annuity option creates longevity and interest rate risk because the rate is fixed in advance.
  • Saying lapses are always bad for the insurer. Fix: Compare the surrender value paid with the reserve released and with unrecovered acquisition costs. Lapses can create a loss or a gain depending on that comparison.
  • Treating IBNR as only claims not yet reported. Fix: State your definition. Say whether you include further development on already reported claims.
  • Saying a soft market means insurers are making high profits. Fix: Say that soft markets mean low premiums and weak margins, so profits fall and reserve shortfalls may show later.
  • Mixing up anti-selection and moral hazard. Fix: Anti-selection happens before or at purchase. Moral hazard happens after cover starts. Use that timing test.
  • Listing issues without explaining effects or solutions. Fix: For every issue, write cause, effect on the insurer and at least one control.
  • Saying DC schemes have no risk for the employer or no cost to anyone. Fix: Say the employer's cost is certain, but members bear investment, longevity and conversion risk. Add that poor outcomes can create pressure on employers.
  • Thinking a higher discount rate raises the liability. Fix: Remember that discounting reduces present values. Higher rate means lower liability, so check direction every time.
  • Saying rising interest rates are always bad for insurers. Fix: Check the liabilities. Rising yields lower the PV of liabilities too. Mismatch decides the net effect. Also note surrender risk when rates rise and reinvestment risk when rates fall.
  • Looking at assets alone. Fix: Always compare with liabilities. A risk is only a problem relative to what must be paid.

Exam tips

  • Always tie your points to the product and details in the scenario. Generic lists score poorly.
  • Use the structure risk, effect, action. It keeps answers short and complete.
  • State the direction of adverse experience: for example, fewer deaths is bad for annuities, more deaths is bad for term cover.
  • In MCQs on lapses, check whether surrender value is above or below the reserve before choosing whether lapses help or hurt.
  • Add one line on customer fairness or regulatory capital in longer answers. Examiners look for this wider view.
  • Structure answers as issue, cause, effect, response. Examiners reward reasoning, not lists.
  • Use general insurance terms precisely: IBNR, retention, quota share, excess of loss, earned premium.
  • In comparison questions, set out life and general points side by side in prose: contract length, claim uncertainty, key assumptions and reserving.