[[Actuarial Notes Wiki|Wiki]] / [[Exam 5 (CAS)]] / **Four Principles of Ratemaking**
## Definition
==Four Principles of Ratemaking== The Four Principles of Ratemaking are fundamental guidelines established by the Casualty Actuarial Society for developing insurance rates that are actuarially sound and equitable.
## The Four Principles
### 1. A rate is an estimate of the expected value of future costs
**Key Points:**
- Rates are prospective (forward-looking)
- Based on probabilistic estimates
- Include all costs: losses, expenses, profit
- Reflect uncertainty and variability
**Application:**
- Use statistical methods
- Consider loss development
- Apply appropriate trends
- Include risk load for uncertainty
### 2. A rate provides for all costs associated with the transfer of risk
**Components to Include:**
- **Losses** - Expected claim payments
- **Loss Adjustment Expenses (LAE)** - ALAE and ULAE
- **Underwriting Expenses** - Acquisition and general expenses
- **Profit and Contingencies** - Return on capital, risk margin
- **Premium Taxes and Fees** - Regulatory assessments
**Formula:**
```
Rate = (Losses + LAE) / (1 - UW Expenses - Profit - Taxes)
```
### 3. A rate provides for the costs associated with an individual risk transfer
**Risk Classification:**
- Rates should reflect individual risk characteristics
- Group similar risks together (homogeneity)
- Differentiate when actuarially justified
- Balance equity and practicality
**Considerations:**
- Statistical significance
- Operational feasibility
- Regulatory constraints
- Social acceptability
### 4. A rate is reasonable and not excessive, inadequate, or unfairly discriminatory
**Reasonableness Tests:**
**Not Excessive:**
- Returns reasonable profit
- Competitive with market
- Justified by costs
- Not exploitative
**Not Inadequate:**
- Covers expected costs
- Maintains solvency
- Sustainable long-term
- Protects policyholders
**Not Unfairly Discriminatory:**
- Reflects actual differences in risk
- Based on objective criteria
- Statistically supported
- Applied consistently
## Application in Practice
### Rate Review Process
1. Estimate expected costs (Principle 1)
2. Include all cost components (Principle 2)
3. Develop classification structure (Principle 3)
4. Ensure reasonableness (Principle 4)
### Regulatory Compliance
Most states require rates to be:
- Adequate (not inadequate)
- Not excessive
- Not unfairly discriminatory
These directly correspond to Principle 4.
### Documentation
Rate filings should demonstrate:
- Methods used (Principle 1)
- Cost allocations (Principle 2)
- Classification rationale (Principle 3)
- Reasonableness testing (Principle 4)
## Examples
### Principle 1 Application
```
Developing auto liability rates:
- Project future losses from historical data
- Develop to ultimate
- Trend to rating period
- Account for uncertainty
```
### Principle 2 Application
```
Premium calculation includes:
Pure Premium: $250 (losses + LAE)
Variable expenses: 20%
Fixed expenses: 10%
Profit & contingency: 5%
Rate = $250 / (1 - 0.20 - 0.10 - 0.05)
= $250 / 0.65
= $385 per exposure
```
### Principle 3 Application
```
Auto insurance territories:
- Urban high-density: Higher rate (more accidents)
- Rural low-density: Lower rate (fewer accidents)
- Suburban: Medium rate
Each reflects actual risk differences
```
### Principle 4 Application
```
Testing reasonableness:
- Compare to industry benchmarks
- Verify profit margin is competitive
- Check for anti-selection
- Ensure sufficient solvency margin
```
## Conflicts and Trade-offs
### Precision vs. Practicality
- More classes = more precise (Principle 3)
- But may reduce credibility (Principle 1)
- Balance needed
### Cost Recovery vs. Competitiveness
- Full cost recovery (Principle 2)
- But must remain competitive (Principle 4)
- Market considerations apply
### Individual Equity vs. Social Goals
- Actuarial fairness (Principles 3, 4)
- But societal concerns
- Regulatory intervention may occur
## Related Concepts
- [[Rate Adequacy]]
- [[Rate Equity]]
- [[Rate Not Excessive]]
- [[Rate Not Unfairly Discriminatory]]
- [[Classification Ratemaking]]
- [[Homogeneity]]
## References
- CAS Statement of Principles Regarding Property and Casualty Insurance Ratemaking (1988)
- Werner & Modlin, Chapter 1
- ASOP 12 (Risk Classification)