General insurance: the combined ratio and the float

A general insurer — motor, health, property — pays out more in claims and running costs than it collects in premiums, and is a thoroughly good business anyway. That is not a contradiction to be explained away; it is the ordinary state of affairs in general insurance, and it turns on a fact that has no equivalent in most industries. The insurer collects premiums today and pays claims months or years later, so at any moment it is sitting on a large pool of other people's money — the float — which it invests in the meantime. It has two engines: the insurance itself, and the investment income on the float. It can run the first at a loss and still make money on the second. illustrative

The number that reads the first engine is the combined ratio: claims paid plus expenses, as a percentage of premiums earned. Below 100, the insurer makes an underwriting profit — it collected more than it paid out. Above 100, it makes an underwriting loss. But a combined ratio of 102% does not mean the insurer lost money; it means underwriting lost 2%, which the float's investment income may more than cover. The whole business can be profitable while the insurance runs at a loss, which is exactly the case that a reader trained on ordinary businesses will misjudge.

This module reads a two-engine business. It teaches the combined ratio and its parts, the float and why it is the quiet heart of the value, and the one judgement that sits behind the reported numbers the way provisioning sits behind a bank's: reserve adequacy. A combined ratio is only as honest as the reserves behind its claims figure, and an insurer that sets aside too little for claims already incurred can manufacture an underwriting profit that reverses a year or two later.

The life-insurance module read a business where profit emerges over decades. General insurance is different again: the policies are short — usually a year — so the profit is more timely, but it arrives through two channels that must be read separately, and one of them is easy to miss entirely. This module exists because judging a general insurer on its bottom line, or worse on its combined ratio alone, misses how the business actually makes money and where the risk actually sits.

Three ideas carry it. The combined ratio is claims plus expenses over premiums — the measure of whether the underwriting itself makes or loses money, with 100 as the dividing line. The insurance float is the pool of premiums held against future claims, invested for the insurer's own account; for many general insurers the investment income on the float is where most of the profit really comes from, which is why a business can lose on underwriting and still compound. And reserve adequacy is the honesty check: whether the insurer has set aside enough for claims that have occurred but not yet been fully paid, because under-reserving lowers the claims ratio and flatters the combined ratio now, at the cost of a top-up later.

Without this module, three errors follow. A reader treats a combined ratio above 100 as "losing money" and rejects a fine insurer. A reader admires a falling combined ratio without asking whether it came from better underwriting or thinner reserves. And a reader credits a profit that was really a one-off equity gain on the float, mistaking market luck for underwriting skill. The point is to read the two engines separately, and to distrust the combined ratio until you have looked at the reserves behind it.

Take the two engines in turn, then the judgement behind them.

The combined ratio — the underwriting engine. Add the claims ratio (claims paid as a percentage of premiums earned) to the expense ratio (costs of running the business, similarly). Their sum is the combined ratio. Below 100, the insurer paid out less than it took in and made an underwriting profit; above 100, it made an underwriting loss. A combined ratio of 102% is an underwriting loss of 2% of premium — real, but small, and not the whole story.

The float — the investment engine. Because premiums come in before claims go out, the insurer permanently holds a large pool of money that belongs, in effect, to future claimants but is the insurer's to invest until the claims fall due. That is the float. Invested at even a modest yield, a float several times the size of annual premium throws off investment income that can dwarf the underwriting result. For a well-run general insurer, the float is where much of the value compounds, and an underwriting loss of a few percent is a small price for holding it.

Putting the engines together. Profit before tax is the underwriting result plus the investment income on the float. An insurer with a 102% combined ratio and a strong float can be more profitable than one with a 98% combined ratio and a weak float. So you never read the combined ratio in isolation; you read it against the investment income the float produces, and you ask which engine is doing the work.

Reserve adequacy — the judgement behind the claims ratio. Here is the lever. When a claim has occurred but not yet been paid or even fully assessed, the insurer must estimate it and set aside a reserve. Set the reserve too low and the claims ratio looks better than reality, the combined ratio improves, and this year's underwriting result flatters — until the claims are actually settled and the shortfall lands as a reserve top-up. This is the general-insurance twin of a bank's provisioning: the reported underwriting profit is only as honest as the reserves behind it, and an improving combined ratio built on thinning reserves is a warning wearing the costume of an achievement.

The two-engine structure and the float are specific to insurance, and they read quite differently even from a life insurer, let alone a manufacturer.

The inversion is that a general insurer profits from holding other people's money, and can run its actual insurance at a loss while doing so. No manufacturer has a float; its money is its own, tied up in inventory and plant. The insurer's float is the opposite — a large, cost-free (or better than cost-free) pool that grows as the business writes more premium, and the investment income on it is a second profit engine bolted to the first. This is why the greatest insurance investors have always cared more about the size and cost of the float than about the combined ratio in any single year: a combined ratio slightly above 100 that lets the insurer hold a large, growing float cheaply can be worth far more than a combined ratio of 95 on a small one. The float, not the underwriting margin, is where the compounding lives.

Read the composite general insurer's fifth year. Its combined ratio is 102% — a claims ratio of 72% plus an expense ratio of 30% — so its underwriting result is a loss of ₹180 crore on ₹9,000 crore of net earned premium (the premium it keeps and has actually earned over the year). Read that number alone and you would call the business unprofitable. illustrative

Now read the second engine. The insurer holds an investment float of ₹14,000 crore — premiums collected against claims not yet paid — and earns 8% on it, or ₹1,120 crore of investment income. That comfortably covers the ₹180 crore underwriting loss and leaves a profit before tax of ₹940 crore. The business makes money; it just makes it on the float, not on the insurance. And the float is durable: as the insurer writes more premium each year, the float grows, and the investment income grows with it. That compounding pool, not the combined ratio, is the heart of the value.

Then look at the weak year, the composite's third, to see both engines wobble at once. A claims spike pushed the combined ratio to 104% — an underwriting loss of ₹308 crore — and a soft investment year cut the float yield to 6.5%, so investment income fell to ₹767 crore. Profit before tax nearly halved, to ₹459 crore. That is the risk of the model laid bare: in a bad year the underwriting loss widens and the float earns less at the same time, and the two engines that usually offset can both misfire together. Reading only a good year would miss how the profit behaves under stress.

The habit to build: read a general insurer as two engines, never one. Take the combined ratio to judge the underwriting, but treat a figure a little above 100 as normal, not as a loss. Then read the float — its size relative to premium and the yield it earns — because that is where much of the profit and nearly all of the compounding comes from. And before trusting either, check the reserves behind the claims ratio: an improving combined ratio on thinning reserves is a top-up waiting to happen. Judge the insurer on the durability of its float and the honesty of its reserves, not on the combined ratio in a single year.

Set the claims and expense ratios to build the combined ratio, then set the float's yield, and watch the two engines combine into profit. Then tick the under-reserve box and see the flattery appear.

Push the combined ratio above 100 and the underwriting result goes negative — yet raise the float yield and the overall profit stays positive, because the float covers the underwriting loss. That is the module's central point in one motion: insurance can lose money while the business makes it. Then tick under-reserve, and the combined ratio drops a few points while a deferred top-up appears alongside it — the reported improvement is borrowed from a future year. The tool makes both truths physical: the float is the quiet engine, and the combined ratio is only as honest as the reserves behind it.

The combined ratio tells you whether underwriting made or lost money this year, but not whether the reserves behind it are adequate — and that is the number that most often deceives. Reserves for claims incurred but not reported, and for claims still being assessed, are estimates, and an insurer that estimates them low reports a lower claims ratio and a better combined ratio with no change in the actual claims experience. The combined ratio is the visible number; reserve adequacy is the hidden one behind it, and the combined ratio cannot certify its own honesty. Only the reserve-development disclosures — how previous years' reserves turned out against what was set aside — can, and they lag by years.

Nor does the float's current investment income tell you how durable it is. A float earning steady interest on high-grade bonds is repeatable; a float that produced a big number this year through equity-market gains is not, and the two look identical on the profit line. An insurer can paper over weak underwriting with a good market year, and a reader who does not decompose the investment income into steady yield versus one-off gains will mistake market luck for a durable second engine. The income is real; its repeatability is the question the headline does not answer.

And neither number captures catastrophe risk, which is the tail that defines general insurance. An insurer can report an excellent combined ratio and a fat float for years and then face a single flood, earthquake or pandemic year that overwhelms both — a loss so large it dwarfs the accumulated underwriting profits. The combined ratio is an average of ordinary years; the business's real risk lives in the extraordinary one, in how much catastrophe exposure the insurer has written and how much of it is reinsured — passed to another insurer to carry, in exchange for a share of the premium. That sits in the risk and reinsurance disclosures, not in the combined ratio or the float, and it is the part that turns a steady compounder into a solvency event — a loss big enough to threaten the insurer's ability to pay its claims.

How it comes up. When a combined ratio improves, a sharp analyst asks whether it was underwriting or reserving. The question sounds like this: "Your combined ratio improved 300 basis points, mostly on a lower claims ratio. How much of that is genuine loss-ratio improvement versus favourable reserve development, and what did prior-year reserves develop to this year?" The analyst is checking whether the improvement is real underwriting or a release from reserves that were set high before — or, worse, thin reserves now.

A good answer, verbatim-style.

"Fair question. Of the 300 basis points, about 200 is genuine — we re-priced the motor book and exited two loss-making segments, and the current-year loss ratio is down accordingly. About 100 basis points is favourable prior-year development: reserves we set in earlier years proved a little conservative and released. Our reserve-development triangle, on page 180, shows consistent small favourable development, not a reversal, and our IBNR is up in line with premium. So the improvement is mostly current-year underwriting, and the reserving remains prudent."

It splits the improvement into current-year underwriting and prior-year development, points to the reserve triangle, and confirms the reserving stance. It lets you separate real from released.

An evasive answer, verbatim-style.

"We're very pleased with our combined-ratio improvement, which reflects our underwriting discipline and pricing sophistication. Our reserving philosophy has always been prudent and is reviewed by our appointed actuary. We're confident this reflects the structural quality of our book and expect the trajectory to continue."

Reassuring and unusable. It never splits the improvement, never mentions prior-year development, and gives no reserve-triangle figure. "Prudent reserving philosophy" is the same claim an under-reserving insurer would make, and "expect the trajectory to continue" implies a re-priced book and a reserve release are the same durable thing, which they are not.

The follow-up nobody asks. "Show us the reserve-development triangle: how did each of the last five years' reserves develop, and was any of this year's profit a release from them?" That forces the reserving history into daylight. Watch what happens when it is not asked. If "prudent philosophy, disciplined underwriting" is allowed to stand, an investor credits a reserve release or a thin reserve as underwriting skill. The silence is the tell — either the reserve development is unflattering, or the current reserves would not survive being shown year by year.

The first trap is reading a combined ratio above 100 as a failing business. It is a genuine underwriting loss, but it is only one of two engines, and the investment income on the float can more than cover it. Some of the finest general insurers run combined ratios slightly above 100 for years, because holding a large, growing float cheaply is worth more than squeezing out an underwriting profit on a smaller one. A reader who rejects every insurer with a combined ratio over 100 is discarding exactly the businesses whose value is in the float.

The second trap is admiring a falling combined ratio without checking the reserves. A lower claims ratio can mean better underwriting — or it can mean the insurer set aside too little for claims already incurred, which flatters the claims ratio now and forces a top-up later. The improvement looks like skill and is sometimes just thin reserving, and the two are indistinguishable on the face of the combined ratio. The check is the reserve-development history: an insurer whose prior reserves consistently prove adequate is improving honestly; one whose reserves keep developing adversely is manufacturing today's combined ratio at tomorrow's expense.

The third trap is treating investment income on the float as uniform quality. Steady interest on high-grade bonds is a durable, repeatable engine; a large equity-market gain in a good year is not, and it can reverse. An insurer with weak underwriting and a big one-off market gain can report the same profit as one with solid underwriting and steady float income, and only decomposing the investment income tells them apart. The profit is identical; the durability is not, and the reader who reads the total and skips the composition credits this year's market to the insurer's skill.

So before you conclude a falling combined ratio is proof of a better insurer, ask: what would change your mind? A history of prior reserves developing adversely, an improvement driven by thin reserving rather than pricing, or a profit leaning on one-off market gains instead of steady float income — any one of those turns "improving underwriting" into "borrowing from next year." If you cannot name in advance the figure that would flip your read, you are admiring the combined ratio, not interrogating it.