Insurance Float: How Carriers Profit

Most homeowners think of insurance as a simple exchange: you pay a premium, and if something goes wrong, the carrier pays your claim. The reality is more complex — and understanding how carriers actually make money explains why your premiums keep rising even when you have never filed a claim. This is one of the most important and least understood dynamics in homeownership, and it is almost completely absent from the real estate books that most buyers rely on.

Gary Keller's The Millionaire Real Estate Investor mentions insurance as a carrying cost in rental property analysis. Robert Kiyosaki's Rich Dad Poor Dad barely addresses insurance at all. Neither book explains the float mechanics that drive premium escalation — the single largest structural force increasing homeownership costs in the 2020s. The Resale Trap dedicates two full chapters to insurance mechanics because the data shows it is one of the largest components of the 25-year cost gap between new and resale homes.

What Is Float?

When you pay your annual homeowner's insurance premium, that money does not sit in a vault waiting for your claim. It enters a pool — the float — that the carrier invests immediately. The float is the total sum of all premiums collected but not yet paid out as claims.

For a large carrier, float is measured in tens of billions of dollars. This is not metaphorical — it is a specific, reported financial figure that appears in carrier financial statements and regulatory filings.

The Berkshire Hathaway Example

No company illustrates float economics better than Berkshire Hathaway. Warren Buffett has written extensively about float in his annual letters to shareholders, calling it one of the most important drivers of Berkshire's success.

As of Berkshire Hathaway's most recent annual report, total insurance float exceeded $168 billion. This money — collected from policyholders across GEICO, General Re, Berkshire Hathaway Reinsurance, and Berkshire Hathaway Primary — is invested in equities (including massive positions in Apple, Bank of America, and Coca-Cola), bonds, real estate, and wholly owned businesses.

Here is what makes float extraordinary as a business model:

• Cost of float: In years when Berkshire's insurance operations run a combined ratio below 100% (meaning they collect more in premiums than they pay in claims and expenses), the float is essentially free money — policyholders are paying Berkshire to hold and invest their premiums. In years when the combined ratio exceeds 100%, the "cost" of float is the underwriting loss, which Buffett has described as typically far less than what Berkshire would pay in interest to borrow the same amount.
• Scale of investment income: Berkshire's investment income from float-funded assets exceeds $10 billion annually in most years. This dwarfs the underwriting profit or loss.
• Duration: Float is remarkably stable. Unlike a bank loan that must be repaid on a schedule, insurance float is continuously replenished as new premiums are collected. As long as the carrier writes new policies, the float persists and grows.

Buffett has explicitly called float "better than free" — it is money that generates investment returns while costing less than any alternative form of capital.

How Every Carrier Uses Float

Berkshire Hathaway is the most famous example, but every insurance carrier operates on float economics. State Farm, USAA, Allstate, Liberty Mutual, Nationwide, and every regional carrier invest their premium float in:

Bond Portfolios

The largest allocation for most carriers. Insurance regulators require carriers to maintain solvency reserves, and investment-grade bonds satisfy these requirements while generating predictable interest income. NAIC financial data shows that the average property/casualty carrier holds 60-70% of its investment portfolio in bonds.

Equities

Carriers allocate a smaller portion (typically 15-25%) to equity investments. These generate higher long-term returns but with more volatility. Regulatory capital requirements limit equity exposure, but the allocations are still substantial in absolute dollar terms — a carrier with $20 billion in float might hold $3-5 billion in equities.

Real Estate and Alternatives

Some carriers invest in commercial real estate, private equity, and other alternative assets. These allocations are smaller (5-10%) but are growing as carriers seek yield in a competitive bond market.

The Net Effect

Insurance Information Institute (III) data shows that the U.S. property/casualty industry generated approximately $80-100 billion in net investment income annually in recent years. This is money earned from investing policyholder premiums — your premiums — between the time they are collected and the time claims are paid.

Why Float Changes the Game for Homeowners

The investment income generated by float often exceeds the carrier's underwriting profit. In some years, carriers run a combined ratio above 100% — meaning they pay out more in claims and expenses than they collect in premiums — and still report a profit because float investment income more than covers the underwriting loss.

This creates a counterintuitive incentive: carriers are motivated to collect as many premiums as possible, even at loss ratios that appear unprofitable on an underwriting-only basis. More premiums mean more float. More float means more investment income. The underwriting loss is an acceptable cost of acquiring float.

Premiums Rise Even When Claims Frequency Drops

If investment returns are strong, carriers want more float. They may expand aggressively into new markets, which eventually drives loss ratios up as they insure riskier properties to grow. When losses materialize, carriers file for rate increases to restore margins. But the rate increases do not return to prior levels when conditions improve — because the higher premiums generate more float. The cycle ratchets upward.

NAIC data shows that homeowner insurance premiums have increased nationally in every single year since 2014. Not once has the national average premium decreased year-over-year, even in years with below-average catastrophe losses. Float incentives explain why.

Claim-Free Policyholders Get No Meaningful Reward

Your premium is set by actuarial models based on your risk pool — location, home age, construction type, roof age, claim history of your ZIP code — not primarily your personal claim history. Some carriers offer minor claim-free discounts (3-5%), but these are trivial compared to the base premium increases. The carrier's real concern is float volume, not individual policyholder behavior.

Rate Increases Are Stickier Than Rate Decreases

When costs rise (reinsurance hardening, catastrophe losses, material cost inflation), carriers file for rate increases promptly. When costs stabilize, carriers rarely file for rate decreases because lower premiums mean less float. NAIC rate filing data shows that for every rate decrease filing, there are approximately 8-12 rate increase filings across the industry. Regulatory lag means approved rate increases remain in effect long after the conditions that justified them have changed.

Reinvestment Risk and the Interest Rate Connection

Float economics are sensitive to interest rate environments. When interest rates are high, carriers earn more on their bond portfolios, which makes float more valuable and can moderate the urgency for premium increases (because investment income is higher). When interest rates are low — as they were from 2009-2021 — carriers earn less on their bond portfolios and must compensate through higher underwriting margins, which means higher premiums.

The post-2022 rate environment has pushed bond yields higher, which theoretically should ease premium pressure through higher investment income. But carriers have simultaneously faced record catastrophe losses, reinsurance hardening, and construction cost inflation — which has overwhelmed the investment income improvement. The net result: premiums continue to rise at 8-10% annually despite better investment conditions.

This dynamic illustrates why simplistic analyses of insurance costs — like those in The Millionaire Real Estate Investor — fail to capture what homeowners actually experience. Keller's framework treats insurance as a fixed percentage carry cost. The reality is a multi-variable equation driven by float economics, reinsurance cycles, catastrophe frequency, and construction cost inflation — all of which The Resale Trap models in its insurance crisis analysis.

The Reinsurance Layer

Your carrier does not keep all the risk. It cedes a portion to reinsurers — companies like Munich Re, Swiss Re, and Hannover Re — which absorb catastrophe losses above a threshold. Reinsurers, in turn, access capital markets through catastrophe bonds (CAT bonds) and industry loss warranties (ILWs).

Each layer takes margin. Your premium funds your carrier's float. The carrier's premium to the reinsurer funds the reinsurer's float. CAT bond investors demand yields that compensate for catastrophe risk — typically SOFR + 5-12% depending on risk tier and attachment point.

The global CAT bond market exceeds $45 billion in outstanding issuance, according to Artemis catastrophe bond data. This market has grown dramatically since 2010 as institutional investors (pension funds, hedge funds, sovereign wealth funds) have sought uncorrelated returns. While CAT bonds provide important capacity to the insurance market, they also add a cost layer that ultimately passes through to policyholder premiums.

By the time your $3,000 annual premium has been sliced through this chain, multiple entities are earning investment income on portions of your money. Understanding this chain does not reduce your premium — but it reframes the economics of choosing what kind of home to buy.

What This Means for the Build-vs-Buy Decision

Understanding float does not reduce your premium. But it reframes the decision about what kind of home to own. New homes with modern building code compliance, impact-resistant materials, and new mechanical systems enter the insurance market at the lowest available premium tier. Resale homes, with older systems and higher loss probability, enter at a higher tier. Over 25 years of compounding at 8-10% annually, that initial gap widens dramatically.

Consider the math:

• New build starting premium: $1,800/year
• Comparable 20-year-old resale starting premium: $2,800/year
• 25-year cumulative cost at 8% CAGR: New = $132,000; Resale = $205,000
• 25-year insurance gap: approximately $73,000

In high-risk states (Florida, Louisiana, Texas coastal), where the starting gap is wider and the escalation rate is higher, the 25-year insurance differential exceeds $100,000.

The Resale Trap quantifies this gap state by state, showing that in high-risk markets, the insurance cost differential between new and resale is one of the largest single components of the total cost of ownership gap. The hidden costs of resale homes compound this further when you add maintenance, capex, and opportunity cost.

What Gary Keller Missed

To be fair to Gary Keller, The Millionaire Real Estate Investor was published in 2005 — before the insurance market transformation that began accelerating around 2017. The book's treatment of insurance as a predictable, modest carrying cost was reasonable for its era. Property insurance premiums were relatively stable, carrier markets were competitive, and CAT bond markets were nascent.

But the world has changed. The reinsurance market has hardened structurally. Climate-driven losses have increased in frequency and severity. Carrier exits from catastrophe-exposed states have accelerated. Construction material costs for claims have inflated faster than general CPI. The insurance carrying cost that was a footnote in 2005 is now one of the largest and fastest-growing components of homeownership cost.

The Resale Trap updates the insurance analysis for the current market, modeling three escalation scenarios across all 50 states and showing how float mechanics, reinsurance cycles, and carrier exits interact to drive premiums on a trajectory that most homeowners — and most real estate books — fail to anticipate. The 395-page analysis is available on Amazon. If you want to understand why your premium doubled and what it means for your next home purchase, the insurance chapters are a good place to start.