Cost of Float
The difference between what Berkshire pays in claims and expenses versus the premiums it collects — determining whether insurance float is a free asset or a costly liability.
“When our cost of float is less than the cost of long-term government bonds, we are being paid to hold other people's money. It is a fantastic business model when executed with underwriting discipline.”
Concept Analysis
Definition & Origins
Underwriting discipline is the practice of accepting insurance risks only when the premiums charged are expected to cover both claims and operating expenses — generating underwriting profit, not just float. Berkshire's insurance operations are categorically built on this principle: accept only profitable business, even if that requires shrinking premium volume during cycles of inadequate industry pricing.
Core Ideas
The combined ratio is the discipline measure. A combined ratio below 100% means underwriting profit — the insurance operation earns more from premiums than it pays in claims and expenses, and then earns investment income on top of this. A combined ratio above 100% means underwriting loss — the insurer is effectively paying for the privilege of holding investable float. Berkshire's multi-decade goal: combined ratio below 100% even in above-average catastrophe years.
The courage to shrink. From 1986 to 1999, National Indemnity's premium volume declined steadily because the company refused to follow competitors in accepting inadequate pricing. Watching revenues shrink while competitors boasted growth — and received Wall Street praise — is a genuine test of cultural discipline. Berkshire's willingness to accept shrinkage during soft markets is the mechanism that preserves underwriting quality in hard markets.
Catastrophe capacity as competitive advantage. Berkshire maintains surplus capital specifically to write enormous risks that other insurers cannot accept — single risks of $1-10 billion in potential loss that would destabilize any normally capitalized insurer. This genuine capacity to bear catastrophic risk, rather than merely theoretical capacity, creates a pricing advantage in mega-risk markets where Berkshire has virtually no competition.
Practical Application
The 2017-2018 hurricane and wildfire seasons resulted in the largest catastrophe losses in Berkshire's history. Despite paying billions in claims, Berkshire remained profitable overall and did not reduce its catastrophe capacity afterward. This resilience — possible because of decades of accumulated float and disciplined underwriting that avoided writing bad business even in low-loss years — is the practical payoff of underwriting discipline.
Common Misconceptions
Misconception 1: All insurance float is valuable. Float generated by unprofitable underwriting costs more than the investment returns it enables. If the combined ratio is 105%, Berkshire effectively borrows at 5% — payable in claims — to invest in assets earning perhaps 3-5%. This is capital destruction, not float advantage.
Misconception 2: Market share is the goal in insurance. Several insurance companies have grown premium volume dramatically by accepting inadequate pricing — generating float but destroying capital. Berkshire's float is valuable because it is accompanied by underwriting profit or at most minimal underwriting cost. The size of the float matters less than its cost.
Thought Evolution
Related Concepts
Case Companies
The 14-year premium shrinkage: the clearest demonstration that refusing bad business creates more value than accepting it
From undisciplined expansion to disciplined growth: the recovery that demonstrated discipline's value through contrast with its absence
The positive case: building the world's largest catastrophe capacity through disciplined pricing in every market cycle