Insurance Principles

The core of Berkshire Hathaway’s success in insurance is a strict adherence to a specific set of underwriting and operational principles. These principles help Berkshire avoid the "herd behavior" that frequently leads the insurance industry into periods of massive losses.

The Four Underwriting Rules (2001)

In the 2001 Letter, following the failures at General Re that were exposed by 9/11, Buffett codified four non-negotiable rules for all Berkshire insurance managers:

1. Circle of Competence: Managers must accept only those risks that they are able to properly evaluate. They must assess all relevant factors, including remote loss scenarios, and ensure the policy carries an expectancy of profit.
2. Limit Aggregation: They must limit the business they accept in a manner that guarantees they will suffer no aggregation of losses from a single event (or related series of events) that will threaten their solvency. This requires a ceaseless search for correlation among seemingly unrelated risks.
3. Avoid Moral Risk: They must avoid business involving "moral risk"—the danger of doing business with dishonest or unethical people. As Buffett says, "trying to write good contracts with bad people doesn’t work."
4. Walk Away: Insurers must ignore market-share considerations and be willing to walk away (even if it means a massive drop in premium volume) if competitors are offering foolish prices or policy conditions.

The Cost of Float Test

Buffett uses a simple test to determine if an insurance business is a "good" one:

• Success: The cost of Float is lower than the cost the company would otherwise incur to obtain funds.
• Lemon: The cost of float is higher than market rates for money.

Experience vs. Exposure

A key pillar of Berkshire's philosophy since 2001 is the prioritization of exposure (the total potential loss) over experience (the historical record).

• See Experience vs Exposure

✅ 2002: Validation of Discipline

In the 2002 Letter, Berkshire saw the validation of these principles as General Re returned to an underwriting profit after two disastrous years.

Discipline over Geography

Buffett emphasized that for a global reinsurer, it is better to have zero business in a certain territory than to have underpriced business.

• Faraday Syndicate (Lloyd's): He used Berkshire's Faraday subsidiary as an example of staying disciplined even when competitors were rushing into markets.
• National Indemnity Tradition: He highlighted Jack Ringwalt (the founder of National Indemnity) as the archetype of the "intelligent underwriter"—someone who would rather do nothing than do it wrong.

The "Exposure" Imperative

Buffett reiterated that insurance success is a function of temperament, not actuarial genius. The willingness to shrink the company (walk away from premiums) is the ultimate test of an insurance manager.

Quotes

• "What counts in this business is underwriting discipline." — 2001 Letter
• "If you can’t tolerate a $2.5 billion loss, you shouldn't be in the reinsurance business." — 2001 Letter
• "Jack Ringwalt was an underwriting genius not because of his math, but because of his discipline." — (Synthesized from 2002 Letter)

• References: 2001 Letter, 2002 Letter, 2002 Meeting
• Index: index