What it means
Imagine a pension with a dark twist: your income rises every time another member dies. That arrangement, centuries old, is the tontine.
The structure is a pool with a survivorship rule: members contribute capital, the pool pays income, and each death redistributes that member's share among the living. The name honours Lorenzo de Tonti, the Italian banker who proposed the scheme to France in the 1650s, and governments used tontines to raise money for two centuries.
The appeal for issuers was actuarial simplicity, because longevity risk sat with the members, not the state, and the scheme needed no reserve for people living too long. The appeal for members was the survivor's dividend: outlive your cohort and your income grows, with the last survivor historically collecting everything.
The dark reputation was earned in fiction and fraud: murder plots in novels, and real insurance-company abuses that led to bans on tontine-style insurance in the early twentieth century. Modern scholars, including retirement researcher Moshe Milevsky, argue for reviving the design honestly, since pooled longevity sharing solves the retirement problem that annuities price and savers fear.
For a non-finance reader, a tontine is a dinner club where the bill is fixed and the table shrinks every year, so the survivors eat increasingly well on the same subscription. Economists like the revival proposals because the modern versions fix the old flaws.
Transparent pools, regulated oversight, and payout formulas that cap the last-survivor windfall answer the fraud and fairness objections. Several pension systems now study tontine-like designs for decumulation (the spending-down phase of retirement), the phase traditional products handle worst.
In practice
Real-world examples.
Example
A 1905 alumni tontine pays rising pensions as deaths redistribute shares across six decades. Each year the committee divides the same income among fewer names. The survivors' cheques grow without any new money entering the pool.
Example
Fifty survivors from an original two hundred each draw four times the original pension. The arithmetic is simply the same pool income divided among fewer people. The members toast absent friends with genuine ambivalence at the annual dinner.
Example
A pooled retirement fund cannot go bankrupt in the way a guaranteed pension can. Longevity risk stays with the members, and the pool owes no guaranteed amount to anyone. That is why issuers found the design so attractive, and why regulators insist on transparency today.
Formula
Calculation
There is no universal formula, but the mechanics are simple: a survivor's payment equals the total pool income divided by the number of living members. It rises mechanically as the cohort shrinks, with no actuarial adjustment needed as the cohort ages.
Worked example: a pool of 200 members earns $200,000 a year in income. At the start, each member receives $200,000 / 200 = $1,000. After deaths leave 50 members alive, each survivor receives $200,000 / 50 = $4,000, four times the original payment, even though the pool's income has not changed.Case study
Seen in the real world.
This case study is fictional and illustrative. A made-up university alumni club in 1905 forms a tontine scholarship fund: two hundred members contribute equal sums, the endowment pays income to members as pensions, and each death lifts the survivors' payments. The ledgers, kept in copperplate, show the arithmetic doing its quiet work for six decades. By the mid-century meetings, fifty members remain, each drawing four times the original pension, and the annual dinner has developed a tradition of toasting absent friends with genuine ambivalence. The club's actuary, hired late and reluctantly, explains the design's forgotten virtue to the surviving committee: no reserve was ever needed for longevity, because the pool itself absorbs the risk of members living long, and the scheme cannot go bankrupt the way a guaranteed pension can.
The fund's final decades vindicate the modern scholars' interest, as the last dozen members live comfortably on incomes funded by the shares of those who died earlier. The last survivor's 1968 bequest of the remaining capital back to the university closes the ledger. The university's archive of the ledgers draws a steady trickle of researchers, each tracing the same arithmetic. What impresses them is not the romance of the last survivor but the sturdiness of the risk-sharing. The fund paid every obligation for sixty-three years without a sponsor, a guarantee or a bailout.
Watch out
Common mistakes.
- Confusing tontines with Ponzi schemes; a tontine's payouts come from a real invested pool, and survival, not recruitment, drives the growing shares.
- Assuming the historical bans settled the question; bans targeted insurance-company abuses, and modern proposals address those with transparent designs.
- Ignoring selection effects; tontine members historically self-selected for health, which is why pricing and fairness need actuarial care.
Questions
People also ask.
What is a tontine?
A pooled arrangement where members share investment income and each death redistributes the deceased's share among the survivors, raising their payments.
Why did tontines disappear?
Insurance-industry abuses and public distrust led to early twentieth-century bans on tontine-style products in major markets.
Why are they studied again?
Pooled longevity sharing offers retirement income without an insurer's guarantees and capital costs, an answer to annuity pricing and longevity risk.
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