Every answer and its explanation appears here once you have finished the path. Each one then links to the matching glossary entry, where the concept is set out in full with its worked example.
1. A factory fire and a pandemic are both risks. Insurance theory nonetheless puts them in two families. What separates them?
The second strikes very many insureds at once, so it does not pool
All insurance rests on an assumption rarely spelled out because it goes without saying: the losses in a book occur independently of one another, so that the premiums of the many who suffer nothing fund the few who lose everything. A particular risk respects that assumption, an isolated fire striking one insured without affecting the neighbours. A fundamental risk destroys it: it strikes very many insureds at once and wipes out whole classes of assets, so that no reasonable premium can fund a massive accumulation of simultaneous losses. It is therefore not a question of the size of a single loss, and that is the commonest error: one very large isolated loss can be reinsured, a great many medium losses arriving on the same day cannot be reinsured the same way. War is the archetype, which explains why its exclusion is the oldest and steadiest in every insurance contract: it is not drafting timidity, it is the mechanism's limit. Faced with such risks the private market reaches its edge, and the burden shifts to the community, which is the subject of this whole path.
Glossary entry · risque-fondamental2. In 1993, after the IRA bombings in the City of London, British insurers withdrew from terrorism cover. Pool Re was created. How is the scheme built?
A mutual of member insurers, with the state as backstop if the pool is exhausted
The sequence is the one found in almost every scheme in this path, and it is worth seeing whole because it explains their shape: an event reveals the risk to be fundamental, insurers withdraw because they can no longer carry it, the real economy finds itself without cover for assets that still need financing, and the state steps in not to insure itself, but to give the private market back the ability to do so. Pool Re is built on that principle: a mutual of member insurers to which each cedes terrorism risk, backed by a state guarantee intervening only in the last resort, if the pool's funds are exhausted. The market therefore goes on underwriting, pricing and paying claims; what the state brings is the certainty that the extreme will be absorbed. Note that this scheme belongs to a family, with the American TRIA and the French GAREAT, and that it is regularly cited in current debates on a possible public backstop for catastrophic cyber and hybrid warfare, where the same reasoning replays with a new risk.
Glossary entry · pool-re3. GAREAT, created in 2002 after 11 September 2001, absorbed the claims from the November 2015 Paris attacks. How does its two-layer structure work?
A market layer shared among private insurers, then the state-guaranteed central reinsurer
GAREAT's shape says what such a scheme is for: that the market carry what it can carry, and no less. The first layer, the market tranche, gathers the private insurers and reinsurers who share the first losses among themselves up to a ceiling; the second is covered by the central reinsurer, which enjoys an unlimited state guarantee. The order matters: private capital is in the front line and bears the ordinary loss, the state appears only where accumulation exceeds what pooling can fund. Two features are worth knowing. Membership is compulsory for every non-life insurer in the French market on the covered risks, which stops any insurer enjoying the scheme's stability without contributing to it. And the entry threshold targets large commercial risks, aiming the scheme where accumulation is real. The November 2015 attacks put the mechanism to work in the conditions it was created for: losses no individual insurer would have absorbed alone, spread without any carrier being put in difficulty.
Glossary entry · gareat4. The Terrorism Risk Insurance Act, enacted in November 2002, requires American insurers to offer terrorism cover and sets a deductible based on their prior-year commercial premiums. Above it, the federal government reimburses 80 per cent of losses. What sets this apart from a pool?
The state advances the funds, then recoups them through a surcharge on premiums
TRIA answers the same problem as Pool Re and GAREAT, but by a different route worth telling apart. A pool accumulates funds in advance, year after year, and the state pays only once those funds are exhausted. TRIA prefunds nothing: it organises a sharing of losses after the event, the insurer first bearing a deductible computed as a percentage of its prior-year commercial premiums, then the federal government reimbursing 80 per cent above it, up to an annual aggregate cap of one hundred billion dollars. The particularity is what follows, and it is often forgotten: the companies then repay the government through a surcharge on post-event premiums, on terms set by Congress. The state is therefore a provider of cash as much as an insurer of last resort, and the cost comes back to the market in the end. What the scheme changes is measured by what happened without it: after 2001 reinsurers withdrew or drastically limited terrorism cover, and skyscrapers, shopping centres and airports would have found themselves uncovered for want of a carrier.
Glossary entry · tria5. The French CatNat regime, created by the act of 13 July 1982, extends every property policy by operation of law to natural catastrophes recognised by ministerial order. Its uniform surcharge rose from 12 to 20 per cent on 1 January 2025. What does the uniform rate imply?
National solidarity: the exposed and the unexposed pay the same rate
The regime's originality lies in one point: the rate is the same for everyone. An owner in a flood-prone stretch of the Loire pays the same surcharge as an owner in the mountains with no flood exposure at all, and that is an assumed political choice rather than a design flaw. The mechanism is easy to follow: the cover attaches by operation of law to every property policy, the direct insurer indemnifies its insured once the municipality is recognised by interministerial order, then it may reinsure with the state-owned central reinsurer under an unlimited guarantee. What uniformity buys is real: universal cover, with no selection, on perils no insurer would write at the risk price, notably flood and drought-driven soil subsidence. What it costs is equally real and should be named: the price no longer says anything about exposure, so it encourages neither avoiding dangerous areas nor reducing vulnerability. The 2025 increase, the first since 1999, reads in that light: when losses rise and price does not sort, it is the rate that rises for everyone.
Glossary entry · regime-catnat6. Spain's Consorcio de Compensación de Seguros covers so-called extraordinary risks, floods, earthquakes and exceptional storms, along with certain political and terrorism risks, funded by a compulsory surcharge. How does its scope differ from the French regime?
It brings natural perils and part of terrorism under one roof, which France separates
Comparing two neighbouring regimes teaches more than studying one, because the gaps reveal choices one would otherwise take for self-evident. The Spanish scheme gathers into a single category, extraordinary risks, both natural perils and part of political and terrorism risk, where France separates the CatNat regime from GAREAT, with two distinct governances and two distinct fundings. It also acts as an insurer of last resort and of complement, stepping in directly towards insureds when the event falls into the extraordinary category, where the French regime runs through the direct insurer and then public reinsurance. What brings the two models together runs deeper than what separates them: in both, a compulsory surcharge levied on most property policies pools nationally a risk the market cannot carry alone, and in both, membership is not optional, which is the condition for such a scheme to hold. The Spanish model, long-established and financially solid, is often cited as a reference in comparative work.
Glossary entry · consorcio-compensacion-seguros7. The American federal flood insurance programme, created in 1968, runs a structural deficit and accumulates debt to the Treasury after major hurricanes. The Risk Rating 2.0 reform brings premiums closer to real risk. Why is it politically difficult?
It sharply raises the cost of cover for the most exposed, historically underpriced
The programme was created to make good the withdrawal of private insurers from a risk judged uninsurable at market price, and it has carried since inception the contradiction that makes it fragile: its historic rates did not reflect real risk, which kept cover affordable but made the programme structurally loss-making, hence substantial debt to the Treasury after every major hurricane season. Bringing premiums closer to risk, the reform's aim, fixes the mechanics and shifts the difficulty onto those who bear it: precisely the most exposed homes, often coastal and often long occupied, whose premiums rise most because they were the most subsidised. Here is the dilemma common to all these schemes, and it deserves stating plainly: a premium that tells the risk encourages moving away from it but can drive households out of homes they already live in, a premium that hides it preserves affordability but funds building in dangerous places. No regime in this path escapes that trade-off; they merely settle it in different places.
Glossary entry · nfip8. Flood Re, created in the United Kingdom in 2016, lets insurers cede the flood element of eligible household policies at a capped rate, and it is designed as transitional to 2039. What does that end date say?
That the scheme accompanies a transition to risk pricing rather than replacing it
This scheme differs from generalist regimes in two ways, and the second is the more interesting. The first is targeting: Flood Re covers neither everyone nor every peril, it treats a precise difficulty, that of a minority of highly exposed households who would otherwise find no affordable cover, by letting them cede the flood element alone at a capped rate, the whole funded by a levy on all household insurers. The second is the end date. By declaring itself transitional to 2039, the scheme says it is not a solution but a delay, meant to accompany a transition to risk pricing while encouraging reduced vulnerability in the meantime. It is an explicit answer to the moral hazard objection every such regime meets: subsidising insurance for the most exposed homes amounts to indirectly funding staying, or even building, in dangerous places. An end date turns a subsidy into a transition, provided it is kept, which remains the open question of any temporary scheme.
Glossary entry · flood-re9. In 2024, of 318 billion dollars of economic losses from natural catastrophes, 181 billion were covered by no contract. In January 2025 the Southern California fires destroyed more than 18,000 structures, many insured by the insurer of last resort. What does that gap measure?
The share of losses falling directly on private wealth and public budgets
The protection gap is the difference between a risk's total economic losses and those a contract actually covers, private or public. The indicator goes beyond market statistics, and that is why it is worth following: every uninsured loss is absorbed somewhere, directly on household and business wealth, or on public budgets through emergency aid and reconstruction. Saying that 57 per cent of 2024's losses were uncovered therefore says that most of the shock was borne outside any mechanism designed to absorb it. In Europe, according to the European supervisor, only about a quarter of losses from extreme events was insured between 1980 and 2024. The Californian episode of January 2025 shows what comes next, when a public arrangement absorbs what the market has left: the insurer of last resort's exposure had quadrupled since 2015 as private insurers withdrew, and the loss translated into a special assessment of one billion dollars on member insurers. The gap does not disappear, it changes carrier, and it comes back to the market in another form.
Glossary entry · protection-gap