1.3 Principles of Insurance
Key Takeaways
- The Law of Large Numbers lets insurers predict aggregate losses accurately as the pool of similar exposures grows
- Indemnity restores the insured to the pre-loss position with no profit; payment is the lesser of the actual loss or the policy limit
- Insurable interest must exist at BOTH inception AND time of loss for property/casualty insurance, but only at inception for life insurance
- Subrogation lets the insurer recover its payment from a negligent third party after the insured is made whole — preventing double recovery
- Utmost good faith demands full honesty; material concealment, misrepresentation, or breach of warranty can void the policy
The Foundations Every Question Rests On
These principles recur throughout the entire exam, so invest here. They are part actuarial science (Law of Large Numbers) and part contract law (the rest).
Law of Large Numbers
Definition: As the number of similar, independent exposures increases, actual losses converge toward the expected (predicted) losses.
| Pool Size | Predictive Accuracy |
|---|---|
| 100 policies | Low — actual losses swing wildly from expected |
| 10,000 policies | Moderate |
| 1,000,000 policies | High — actual losses hug the prediction |
Worked example: 1,000 homeowners each pay $1,000 → $1,000,000 collected. History says about 90 will suffer a $10,000 loss → $900,000 in claims, leaving $100,000 for expenses and profit. With only ten insureds, one unexpected total loss would wipe out the pool — the principle simply cannot work at small scale.
Principle of Indemnity
Definition: Insurance restores the insured to the same financial position held just before the loss — no better, no worse.
Key rules: payment equals the lesser of the actual loss or the policy limit, and the insured cannot profit from a covered loss.
| Scenario | Insurer Pays |
|---|---|
| Car worth $10,000, $3,000 damage | $3,000 (actual loss) |
| Car worth $10,000, total loss | $10,000 (actual cash value) |
| Car insured for $15,000 but worth $10,000, total loss | $10,000 (cannot exceed actual value) |
Indemnity is enforced through deductibles, other-insurance clauses, coinsurance, and the actual-cash-value (ACV = replacement cost − depreciation) settlement basis. Some contracts modify pure indemnity — valued policies (agreed value, common on fine art) and replacement-cost settlements pay more than strict ACV, but they remain exceptions you should flag.
Insurable Interest
Definition: A financial stake such that loss of the property or person would cause genuine financial harm.
| Insurance Type | When Interest Must Exist |
|---|---|
| Property & Casualty | At inception AND at time of loss |
| Life | Only at inception |
Exam alert: This timing split is tested repeatedly. P&C requires interest at both moments.
Sources of interest: ownership, a mortgagee/secured creditor's stake, a bailee (a dry cleaner holding a customer's coat), a contractual right, or legal liability. Scenario: Mark sells his house to Susan Monday; fire strikes Tuesday before Mark cancels. Mark cannot collect — he no longer owns it (no interest at time of loss); Susan cannot collect — she has no policy yet. Neither recovers. That is why the timing rule exists.
Subrogation
Definition: After paying a claim, the insurer may "step into the shoes" of the insured and pursue the negligent third party who caused the loss.
Order of recovery under the make-whole doctrine
The make-whole doctrine controls how recovered dollars are split when the at-fault party cannot pay everyone in full:
- First — the insured is made whole, including the deductible and any uninsured loss.
- Then — the insurer recovers what it paid out.
- Any surplus remaining goes to the insured.
This corrects a common myth: the deductible is part of the insured's uncompensated loss and is recovered with the insured first, not last. Subrogation prevents the insured from double-recovering (collecting from both the insurer and the wrongdoer), holds negligent parties accountable, and helps hold premiums down.
Principle of Contribution
When two or more policies cover the same loss, each insurer pays its pro-rata share so the insured is not enriched.
- Policy A limit $100,000; Policy B limit $200,000; total $300,000; loss $60,000.
- A pays (100,000 ÷ 300,000) × 60,000 = $20,000; B pays (200,000 ÷ 300,000) × 60,000 = $40,000.
Utmost Good Faith (Uberrimae Fidei)
Insurance demands a higher honesty standard than ordinary contracts because the insurer relies on the applicant's disclosures.
| Concept | Definition | Effect if false/breached |
|---|---|---|
| Representation | A statement believed true when made | If material and false, insurer may void |
| Warranty | A strict promise that must be literally true | Breach can void coverage even if immaterial |
| Concealment | Silence on a material fact | Intentional concealment can void the policy |
| Misrepresentation | A material false statement | Voids if relied upon |
Material means the fact would have changed the insurer's decision to issue or its pricing. A concealed prior arson conviction is unmistakably material.
Representation vs. Warranty — A High-Value Distinction
The difference between a representation and a warranty decides whether a misstatement actually voids coverage, and the exam tests it directly.
- A representation only needs to be substantially true and only matters if it is material. An applicant who honestly believes their roof is five years old (it is six) made an immaterial misrepresentation that will not void the policy.
- A warranty is a strict promise written into the contract that must be literally and continuously true. A commercial property warranty that "a central station burglar alarm is maintained and operational" can void coverage if the alarm is disconnected — even if the disconnection seems minor — because breach of warranty does not require materiality.
Worked scenario: An applicant states "no losses in the past three years" but forgot a small $200 windshield claim. Because that omission is immaterial (it would not have changed underwriting), it is a representation that does not void the policy. Change the facts to a concealed $80,000 fire claim, and the same statement becomes a material misrepresentation that can void coverage. Materiality, not the size of the lie, is the pivot.
How the Principles Reinforce One Another
These principles form an interlocking system rather than six isolated rules. Indemnity caps recovery at the actual loss; insurable interest ensures only those who can suffer real loss may collect; subrogation and contribution stop the insured from collecting twice; and utmost good faith keeps the information flowing to the insurer accurate so the Law of Large Numbers can price the pool correctly. Remove any one pillar and moral hazard creeps in — which is precisely why exam questions often describe a scenario and ask which principle prevents the insured from profiting.
Train yourself to name the principle, not just the outcome.
For property and casualty insurance, when must insurable interest exist?
Under the make-whole doctrine, when a third party's payment is too small to cover everyone, who is paid first from the subrogation recovery?
Two valid policies cover the same $90,000 loss: Policy A with a $60,000 limit and Policy B with a $120,000 limit. Under the principle of contribution, how much does Policy A pay?