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CAS Exam 9 · Integrated Stress and Scenario Analysis · Tutorial 950 of 995

Integrating Catastrophe Shocks

Learn to connect catastrophe assumptions to enterprise loss, reinsurance, short-term funding needs, and capital outcomes.

Advanced 12 min read

What You'll Learn

  • Separate gross catastrophe claims from treaty-eligible losses and nonrecoverable expenses
  • Calculate occurrence-layer recoveries using the attachment point and layer limit
  • Reflect collection risk and distinguish contractual recoveries from collectible amounts
  • Compare event-by-event treaty treatment with an incorrect annual aggregation
  • Map claim payments and reinsurance receipts over time to identify funding gaps
  • Translate the scenario’s net impact into post-stress capital and a coverage ratio

From Catastrophe Narrative to Enterprise Impact

A catastrophe scenario is not fully quantified when an estimate of gross claims has been produced. The enterprise impact also depends on where losses occur, which claims qualify for reinsurance, how the contract applies to each event, when recoveries can be collected, and which expenses are not insured. The same gross loss can therefore produce different net losses and liquidity pressures under different policy and treaty terms.

The analysis should keep three quantities distinct: contractual recovery, collectible recovery under the scenario, and cash received by a specified date. Contractual recovery follows the treaty wording. Collectible recovery allows for an assumed collection haircut or default scenario. Cash received by a date additionally reflects settlement timing. These quantities are not interchangeable.

Definition: For a single occurrence with treaty-eligible loss \(L\), an excess-of-loss layer attaching at \(A\) with limit \(M\) has contractual recovery $$ R(L)=\min\{\max(L-A,0),M\}. $$ The layer pays only the portion of eligible loss above the attachment, up to the stated layer limit. Thus “\(M\) excess of \(A\)” means a layer of size \(M\), not an unlimited layer with some separate maximum.

For an enterprise stress calculation, a useful accounting bridge is $$ \text{net catastrophe impact} = \text{gross claims} + \text{catastrophe expenses} - \text{collectible reinsurance recovery}. $$ This bridge assumes the amounts are measured on a consistent basis and that taxes, investment income, reserve changes, and other offsets are either excluded or separately modeled. If catastrophe expenses are treaty-eligible, their treatment must follow the contract rather than being automatically added as unrecoverable costs.

Why the Layer Formula Works

If \(L\leq A\), the eligible loss does not reach the attachment and the treaty pays zero. If \(A<L<A+M\), the loss above attachment is \(L-A\), so recovery is \(L-A\). If \(L\geq A+M\), the full layer is exhausted and recovery cannot exceed \(M\). Combining these three cases gives the minimum-maximum expression in the definition.

This is an occurrence calculation: \(L\) is the total eligible loss assigned to one occurrence under the contract’s event definition. A treaty applying separately to each occurrence must be calculated separately for each event. Adding losses from distinct occurrences first can change the answer and is not permitted unless the contract provides an applicable aggregate feature.

Worked Enterprise Assessments

Worked Example: Concentrated Event, Collection Haircut, and Capital

Scenario and assumptions. A hypothetical insurer models one windstorm. Gross claims are $120 million, divided among three neighboring zones. Treaty-eligible claims are $42 million, $38 million, and $25 million, respectively. The occurrence treaty is a $50 million layer attaching at $60 million. The scenario assumes that 90% of the contractual recovery is collectible. Catastrophe expenses are $8 million and are not treaty-eligible. Opening available capital is $300 million; the capital requirement is $190 million and is held fixed for this calculation. No tax, interest, investment return, or mortality effect is modeled. This is a deterministic stress calculation, not a probability distribution.

Step 1: Aggregate within the occurrence. The zones are affected by the same modeled event, and the treaty responds to the event total. Eligible claims are $$ L=42+38+25=105\text{ million dollars}. $$ The $120 million gross claims figure includes losses that are not treaty-eligible, so it is not substituted for \(L\).

Step 2: Calculate contractual recovery. The loss above the $60 million attachment is \(105-60=45\) million. The $50 million layer limit does not bind: $$ R=\min\{\max(105-60,0),50\}=\min(45,50)=45\text{ million dollars}. $$

Step 3: Apply the collection assumption. At 90% collectibility, the recovery recognized in this scenario is $$ 0.90(45)=40.5\text{ million dollars}. $$

Step 4: Calculate enterprise impact and capital. Net impact is \(120+8-40.5=87.5\) million dollars. Post-stress available capital is \(300-87.5=212.5\) million dollars. The post-stress capital coverage ratio, defined here as available capital divided by the fixed requirement, is $$ \frac{212.5}{190}=1.1184=111.8\%. $$ The units are consistent: every numerator and denominator in the ratio is in millions of dollars.

Step 5: Check near-term liquidity separately. Suppose $72 million of claims and $5 million of expenses are paid within 30 days, while no reinsurance cash arrives in that period. From $95 million of opening liquid resources, the balance is \(95-72-5=18\) million dollars. The later expected recovery of $40.5 million improves the eventual funding position but does not reduce this 30-day cash outflow.

Method and trap avoided. The method first totals eligible loss for the covered occurrence, then applies the layer, then applies collectibility. A common wrong calculation is to apply the treaty to all $120 million of gross claims without checking eligibility. Here that would give \(\min(120-60,50)=50\) million of contractual recovery, overstating recovery by $5 million before even considering the collection haircut.

Worked Example: Two Events and an Occurrence Limit

Scenario and assumptions. A hypothetical insurer experiences two distinct hail events in one stress year. Event 1 produces $68 million of gross claims, of which $60 million is eligible. Event 2 produces $55 million of gross claims, of which $48 million is eligible. The treaty provides a $30 million layer attaching at $40 million for each occurrence, with no annual aggregate limit or reinstatement issue in this scenario. Collection is certain. Uncovered catastrophe expenses total $9 million. No tax, interest, investment return, or mortality effect is modeled; all figures are deterministic.

Step 1: Calculate recovery for Event 1. $$ R_1=\min\{\max(60-40,0),30\}=\min(20,30)=20\text{ million dollars}. $$

Step 2: Calculate recovery for Event 2. $$ R_2=\min\{\max(48-40,0),30\}=\min(8,30)=8\text{ million dollars}. $$ Total contractual and collectible recovery is \(20+8=28\) million dollars.

Step 3: Calculate the annual net impact. Gross claims total \(68+55=123\) million dollars. Therefore, net impact is $$ 123+9-28=104\text{ million dollars}. $$

Step 4: Trace the cash timing. Assume opening liquid resources are $80 million. By day 10, the insurer pays $50 million of Event 1 claims, $35 million of Event 2 claims, and $4 million of expenses. No recovery has arrived, so the cash balance is \(80-50-35-4=-9\) million dollars. A $20 million recovery arrives on day 45, bringing the balance to $11 million. On day 60, the remaining $38 million of claims and $5 million of expenses are paid, taking the balance to \(-32\) million. The $8 million recovery arrives on day 70, leaving \(-24\) million dollars. With no other cash flows, the maximum funding deficit is $32 million, reached on day 60.

Method and trap avoided. The treaty is applied once to each event because it has an occurrence limit. An incorrect approach would combine eligible losses to get \(60+48=108\) million and calculate one recovery of \(\min(108-40,30)=30\) million. That is not the stated contract: the correct total is $28 million. The cash schedule also shows why eventual net loss alone does not identify the required short-term funding.

Worked Example: Layer Cap, Expenses, and Capital Adequacy

Scenario and assumptions. A hypothetical insurer models a single earthquake with $140 million of gross claims, of which $96 million is treaty-eligible. The occurrence cover is a $25 million layer attaching at $55 million. The scenario assumes 80% of contractual recovery is collectible. Catastrophe expenses are $14 million and are not eligible. Opening available capital is $310 million, and the capital requirement is held fixed at $200 million. No tax, interest, investment return, or mortality effect is modeled; amounts are deterministic except for the explicitly applied collection factor.

Step 1: Apply the attachment and limit. Eligible loss exceeds attachment by \(96-55=41\) million dollars, but the treaty limit is $25 million: $$ R=\min\{\max(96-55,0),25\}=\min(41,25)=25\text{ million dollars}. $$

Step 2: Reflect collection risk. The assumed collectible amount is \(0.80(25)=20\) million dollars. The contractual recovery remains $25 million; $20 million is the amount used in this scenario’s net impact.

Step 3: Calculate net impact and post-stress capital. $$ \text{net impact}=140+14-20=134\text{ million dollars}, $$ $$ \text{post-stress available capital}=310-134=176\text{ million dollars}. $$ The coverage ratio is \(176/200=0.8800\), or 88.0%.

Step 4: Identify the liquidity exposure. Suppose $40 million of claims and $6 million of expenses are paid within seven days, while no recovery arrives for at least 30 days. With $70 million of opening liquid resources, the day-seven balance is \(70-40-6=24\) million dollars. Later claims and expenses can create a further cash need even though the capital calculation already recognizes the assumed collectible recovery. A dated cash-flow projection is needed to quantify that later need.

Method and trap avoided. The treaty payment is capped at the layer limit before collectibility is applied. The wrong calculation \(96-55=41\) million treats the amount above attachment as an uncapped recovery. The corrected contractual recovery is \(\min(41,25)=25\) million, and the scenario’s collectible recovery is then \(0.80(25)=20\) million.

Integration Checks and Common Traps

A catastrophe impact bridge is only as reliable as its event definition, eligibility mapping, and timing assumptions. Concentration matters because nearby risks may be struck by one event and therefore contribute to the same occurrence loss. Conversely, losses in separate events should not be combined merely because they occur in one year. The event definition and any annual aggregate provisions must come from the modeled contract.

1
Set the event and footprint.
Identify which exposures are affected and which losses belong to each occurrence. Preserve relevant location or peril detail until event aggregation is complete.
2
Separate loss components.
Reconcile gross claims to treaty-eligible loss, and identify expenses and other costs that remain outside the recovery calculation.
3
Apply contract terms.
For each covered occurrence, apply the attachment, layer limit, and any stated aggregate or other contract conditions in the correct order.
4
Reflect collection and timing.
Distinguish the contractual amount from the scenario’s collectible amount and from cash received by each projection date.
5
Bridge to enterprise measures.
Calculate net impact, update available capital on a consistent basis, and separately project cash balances through the period of stress.

A capital ratio should state its denominator and basis. In the examples, the ratio is post-stress available capital divided by a fixed capital requirement. If the scenario also changes the requirement, the stressed requirement must be calculated and used; it should not silently be held fixed. Similarly, an expected or haircut recovery may be appropriate for one stress view, while a more severe view may assume no collection. The selected treatment should be explicit and applied consistently.

  • Do not confuse attachment with limit. A “$25 million layer attaching at $55 million” has a maximum payment of $25 million.
  • Do not apply the treaty to gross claims automatically. First determine the eligible loss under the wording.
  • Do not combine separate events without contractual authority. An occurrence layer is calculated for each occurrence.
  • Do not treat a receivable as immediate cash. Claim payment dates and recovery dates can create a funding gap even when eventual net loss is moderate.
  • Do not subtract recovery twice. Use the chosen collectible recovery once in the net impact bridge, and do not also deduct it from gross claims elsewhere.

These checks connect catastrophe severity to the insurer’s actual financial transmission paths: claims, reinsurance, expenses, liquidity, and capital. A concise scenario result should therefore report the gross event impact, eligible loss, contractual and collectible recoveries, net impact, relevant cash-flow dates, and the capital measure used.

Check Your Understanding

For each original scenario, calculate the requested quantities using the stated treaty terms and timing assumptions.

  1. A hypothetical flood produces $75 million of gross claims, of which $64 million is eligible. A certain-collection treaty is an $18 million layer attaching at $50 million. Uncovered expenses are $4 million. What are contractual recovery and net impact? (Answer: Recovery $14 million; net impact $65 million.)
  2. Two separate occurrences have eligible losses of $58 million and $77 million, and gross claims total $150 million. A treaty provides a $20 million layer attaching at $45 million per occurrence. Collection is certain and uncovered expenses are $7 million. What is total recovery and net impact? (Answer: Recovery $33 million; net impact $124 million.)
  3. A single event has $110 million of gross claims, including $90 million of eligible loss. The treaty is a $30 million layer attaching at $50 million, and 75% of contractual recovery is collectible. Uncovered expenses are $10 million. What are contractual recovery, collectible recovery, and net impact? (Answer: Contractual recovery $30 million; collectible recovery $22.50 million; net impact $97.50 million.)
  4. An insurer starts with $60 million of liquid resources. Before any recovery, it pays $48 million of claims and $7 million of expenses. Later, before a $16 million recovery arrives, it pays another $20 million of claims and $3 million of expenses. Assuming no other cash flows, what is the lowest cash balance and the required funding to avoid a negative balance? (Answer: Lowest balance \(-$18 million\); funding required $18 million.)
  5. Available capital is $250 million and the fixed capital requirement is $180 million. A catastrophe causes $85 million of gross claims and $5 million of uncovered expenses. Contractual recovery is $25 million, of which 80% is collectible. What are net impact, post-stress available capital, and the coverage ratio? (Answer: Net impact $70 million; post-stress available capital $180 million; coverage ratio 100.0%.)
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