Ajo is mathematically a closed loop where no money is ever earned — it is only redistributed in time. The first person to "pack" the Ajo collects an interest-free loan from everyone else; the last person has effectively lent their money out for the entire year and gets back exactly what they put in — minus the bite of inflation, the collector's fee, and the silent cost of every opportunity they passed up. This is not a moral failing of Ajo; it is its design. ROSCAs (rotating savings and credit associations) were never built to grow money. They were built to move money to whoever needed it first, in communities where banks were distant, untrustworthy, or hostile. That world is fading. In 2026 Nigeria, with money market funds paying 20–24%, treasury bills paying 16%, and PiggyVest, Cowrywise and PalmPay locking savings at 18–22% with a phone tap, the case for the traditional Ajo has collapsed for anyone who is not the first collector. This report shows the math, names the risks, honours the real reasons people still join, and lays out what a smarter community savings model looks like.
What Ajo actually is
Ajo is a Nigerian rotating savings and credit association: a group of trusted people contribute a fixed sum at a fixed interval, and one member takes the entire pool each cycle until everyone has had a turn. The Yoruba call it Ajo or Esusu, the Hausa Adashe or Adashi, the Igbo Isusu, Osusu, Utu, or Mitiri, the Edo Osusu, the Nupe Dashi, the Ibibio Efe, the Tiv Bam. The system is so old it predates colonial banking — anthropologist William Bascom documented it functioning in cowrie shells in 18th-century Oyo under Alaafin Abiodun. It travelled with enslaved Yoruba across the Atlantic and survives today as Sou-Sou in Trinidad, Partner in Jamaica, Box in Guyana, Sangue in Haiti, and Sou-sou among Caribbean and West African diasporas in the United States. The institution has remarkable cultural retention; the word "Sou-sou" is the Yoruba word "esusu" almost unchanged.
Mechanically, groups range from 5 to 50 members, contributions can be daily, weekly, fortnightly, or monthly, and payout order is set by lottery, by need, by negotiation, or — in commercial ajo gbigba — by a paid collector called the Alajo or "Ajo woman", who walks the markets daily with a thrift card. The collector's standard fee is one day's contribution per 30-day cycle, roughly 3.33%, which the participant never recovers. EFInA's 2023 Access to Financial Services survey found that 10% of Nigerian adults — about 14 million people — rely on informal savings groups as their only financial channel, with usage heaviest among market women, traders, artisans, IDPs, and the rural North-West. Total Ajo participation is far higher because millions of bank-account holders run an Ajo on the side. Notably, EFInA's data also shows informal-only usage has fallen from 14% in 2020 to 10% in 2023 as fintech alternatives spread.
The financial fallacy, in numbers
Take the textbook example: 12 members, ₦10,000 each, every month, for 12 months. Each receives ₦120,000 on their assigned month. Apply Nigeria's actual market rates of 2025–2026 — Monetary Policy Rate at 27%, headline inflation averaging roughly 22–25% across the cycle, and treasury bills at 16%. The mathematics is unforgiving.
Member 1 collects ₦120,000 in month 1 having paid only ₦10,000 that day. They effectively borrowed ₦110,000 from the other eleven members and will repay it in eleven future ₦10,000 installments. Total repaid = ₦110,000. Total borrowed = ₦110,000. The internal rate of return on this loan is exactly 0%. A bank would have charged Member 1 about 30% per year for the same liquidity. Member 12 does the mirror image — pays in ₦10,000 every month for eleven months and finally receives ₦120,000 in month 12. Their IRR is also 0%. They have made an interest-free loan to the group for an entire year. In a closed-form proof, every member's IRR is zero, and the sum of all members' net present values is exactly zero at any discount rate. This is mathematically airtight: total contributions in each month equal total payout, so aggregate cash flow at every time step is zero. Ajo cannot create return; it can only redistribute time-value among members.
The table below shows the net present value each member captures at a 20% annual discount rate — what someone could earn safely in a Nigerian money market fund:
| Position | Payout month | NPV at 20% discount | NPV at 27% (MPR) |
|---|
| 1 | Month 1 | +₦10,250 | +₦13,440 |
| 6 | Month 6 | +₦733 | +₦717 |
| 7 | Month 7 | −₦1,078 | −₦1,675 |
| 12 | Month 12 | −₦9,695 | −₦12,952 |
The cross-over is around position 6. Anyone who collects after the midpoint is the loser in the trade. And this is before any fees.
Now layer inflation. Using a representative 25% annual inflation rate (Nigeria's 12-month rolling average through 2024–2025), the ₦120,000 Member 12 receives in month 12 has the purchasing power of about ₦96,000 in month-1 naira. The break-even payout that would simply preserve the buying power of their twelve ₦10,000 contributions is ₦135,699. Member 12 takes a real loss of ₦15,699 per cycle — about 11.6% of their savings, vapourised. At 30% inflation that loss balloons to ₦17,890; at 35%, ₦20,005. Member 1, by contrast, captures the lump sum at near-full purchasing power and "repays" with naira that is worth less every month — a real wealth transfer of roughly ₦27,000 from the last collector to the first.
The opportunity cost that nobody sees
The deeper hidden cost is what that ₦10,000/month would have done somewhere else. Every Nigerian fintech and SEC-regulated mutual fund has been throwing off double-digit yields throughout 2025–2026. Putting the same ₦10,000/month into each of the most accessible alternatives produces these year-end balances:
| Vehicle | Annual yield | Year-end balance | Surplus over Ajo |
|---|
| Ajo (any position, nominal) | 0% | ₦120,000 | — |
| Nigerian 364-day Treasury Bill (Apr 2026) | 16.20% | ₦130,968 | +₦10,968 |
| PiggyVest SafeLock (1-yr) | 19.5% | ₦133,433 | +₦13,433 |
| Stanbic IBTC Money Market Fund | 20.08% | ₦133,847 | +₦13,847 |
| ARM Money Market Fund | 21.97% | ₦135,191 | +₦15,191 |
| PalmPay SmartEarn | up to 22% | ₦135,212 | +₦15,212 |
| Coronation MMF | 23.74% | ₦136,452 | +₦16,452 |
A SEC-regulated money market fund — Stanbic IBTC, ARM, FBNQuest, Coronation — produces a ₦14,000–₦16,000 surplus over a 12-month Ajo, with full liquidity, no counterparty risk, and a custodian bank holding the assets. Even the worst formal alternative, a basic 5% bank savings account, beats the Ajo's flat ₦120,000. Member 12 is worse off than every formal option in Nigeria. Member 1, the only mathematical winner, would still do better borrowing ₦110,000 from a microfinance bank at 25% and saving the difference — except that Ajo offers him this loan at 0% with no paperwork, which is precisely its appeal.
The risks Ajo participants pretend not to see
Ajo's structural fragility shows up in three places. Default risk is real and unmeasured. Trader Rose Ojoma told VOA in 2024 that collectors "take a month's worth of contributions as an opportunity to run away, and you cannot find them"; she has cut her contributions to limit exposure. Lagos courts have prosecuted Alajo collectors for ₦1.7 million in fraudulent thrift-card loans and ₦15 million in falsified credit-card schemes. BusinessDay reports the absconding chairman is a familiar story across Nigerian markets. Academic surveys in Uganda found ROSCA participants lost about 6% of their saved amounts annually — and Bouman (1995) warned three decades ago that the literature systematically under-reports default because researchers accept members' assurances at face value.
The legal vacuum is total. Nigerian bank deposits are insured by NDIC up to ₦5 million in commercial banks and ₦2 million in microfinance banks (raised in May 2024, covering 99% of all depositors fully). SEC-regulated mutual funds segregate client assets at independent custodians. Ajo has none of this. If your collector vanishes, your only recourse is a civil suit against an individual — usually with no documentary evidence beyond a thumb-printed card. The Nigerian Cooperative Societies Act protects only registered societies, which Ajo groups almost never are.
The "discipline" Ajo is praised for is largely an illusion. Mehnaz Gugerty's 2007 Kenya study, the canonical behavioural-economics defence of ROSCAs, argued they work as commitment devices for people who "can't save alone" because of self-control problems, family demands, or theft. That argument was decisive in 2007. It has been quietly demolished by 2026: PiggyVest SafeLock, Cowrywise Life Goals, MMF auto-debit, Kuda Spend+Save and ALAT Stash all enforce the same illiquidity with SEC or CBN regulation, custodian segregation, NDIC insurance where applicable, and 13–22% yields. Ajo enforces a contribution cycle, not a savings habit. When the cycle ends, the lump sum gets spent, the cycle restarts at zero, and no compounding capital is ever built.
Who actually benefits
Three groups capture real value from Ajo. The collector — the Alajo, the "Ajo woman" — earns roughly 3.33% per cycle and can scale to ₦200,000–₦400,000 monthly running multiple groups; the legendary Alajo Ṣomolu of Lagos ran his thrift business from 1954 until age 95 with no computer, returning the exact notes deposited. Early recipients capture genuine NPV, especially if they use the lump sum productively to restock inventory or buy a sewing machine that produces income. Women in patriarchal households use Ajo as Anderson and Baland (2002) documented in Nairobi: a way to convert cash into illiquid claims a husband cannot demand for "immediate consumption." This is a real welfare gain even at a zero IRR.
But the structure also exploits financial exclusion. The same market woman paying her ₦500/day Adashe is generating roughly 3.3% of her savings as fee income for the collector and 0% return for herself, while across town a SEC-licensed money market fund accessible from her ₦5,000 minimum on Cowrywise is paying 20%. Ajo is the price the unbanked pay for being unbanked. It is not a savings tool; it is a substitute for credit access, dressed in the language of savings.
Why Nigerians still use Ajo — and why those reasons deserve respect
Distance to bank branches in northern Nigeria, the absence of NIN or BVN documentation, hidden bank fees, scarred memories of failed banks, religious objection to interest in Muslim communities, and the genuine warmth of a market-women's circle are not foolish reasons. EFInA's data shows informal-only reliance is highest in the North-West, where formal services are perceived as untrustworthy or culturally distant. The forced-savings discipline of Ajo is genuinely valuable for people whose alternative is spending every naira that touches their hand. The credit access — getting ₦120,000 in month one when your child needs school fees and no bank will lend to you — can change a life trajectory. Anderson and Baland's intra-household protection mechanism is real for Nigerian women whose husbands consider a wife's earnings communal property. None of this should be dismissed.
What has changed is that every single one of these functions can now be replicated, better, by formal alternatives that did not exist in 2007. The commitment device exists in PiggyVest SafeLock. The intra-household protection exists in a personal Cowrywise account a husband cannot touch. The early-credit function exists in microfinance loans, FairMoney, Carbon, and Renmoney. The community function exists in Cowrywise Circles and PiggyVest Squad. The unique value proposition of Ajo has narrowed to one thing: it requires no smartphone, no BVN, and no literacy. For everyone else, the math no longer works.
What the economists actually say
The academic consensus is striking once you read the foundational papers. Besley, Coate and Loury (American Economic Review 1993; Review of Economic Studies 1994) — the most-cited theoretical work on ROSCAs — proved formally that ROSCAs are Pareto-dominated by formal credit markets when those exist, and that the only welfare gain from a random ROSCA is the time-value of receiving a lump sum earlier than autarky. They explicitly noted that the last recipient gains nothing financially and joins only because of social capital. Ambec and Treich (2007) put the puzzle plainly: "the member who receives the pot last could do as well by privately accumulating savings… By backward induction, the rosca should break down." Only commitment problems, intra-household conflict, or absent credit explain why it does not. Handa and Kirton's Jamaica Partner study (1999) confirmed the banker's fee makes the net return negative. Klonner and Rai (2007) showed that even bidding ROSCAs — which generate non-zero implicit interest — suffer adverse selection: riskier borrowers bid hardest for early pots, raising default for late receivers. Khatib-Chahidi (1995) documented Cypriot ROSCAs indexing contributions to gold in inflationary periods — a tacit admission that nominal-cash ROSCAs cannot survive high inflation. The Federal Reserve Bank of Philadelphia's Hevener (2006) walked through the zero-interest arithmetic explicitly. Bouman's classic warning still stands: "Proper investigation is almost impossible without access to books and records," meaning default rates in ROSCAs are systematically under-reported.
The cumulative verdict of forty years of development economics on ROSCAs: they are a second-best institution that exists because of market failures elsewhere, not because of any inherent financial merit, and they are dominated by formal alternatives whenever those become accessible.
A smarter Ajo, designed for 2026
The good news is that Nigerian community savings does not need to die — it needs to upgrade. Three concrete models preserve everything participants love about Ajo while eliminating its structural losses:
The first is the registered Investment-and-Credit Cooperative. Ten or more members register under their state's Cooperative Societies Law (the federal Act is CAP N98 LFN 2004), draft bye-laws specifying contributions and dividend formulas, open a corporate bank account at any DMB (NDIC-covered to ₦5 million at the entity level), and invest 70% of pooled funds in 364-day T-bills at 16.20% and 30% in a money market fund at 21%. The blended yield to members is roughly 17–19% per year, paid as dividend — versus 0% in Ajo. The cooperative has legal personality, audited books, and tax exemption on cooperative income.
The second is the digital savings circle on PiggyVest Squad or Cowrywise Circles. The platform locks the funds, fixes the payout schedule, runs through CBN- or SEC-licensed custody, and pays 13–22% depending on instrument. WeSpare, profiled by TechCabal in March 2026, is a new entrant explicitly marketing itself as "Ajo without the absconding risk" — collections through Anchor (a CBN-licensed MFB), guaranteed missed contributions, and fixed payout dates that never slip.
The third, simplest path is individual self-saving in a money market fund with auto-debit. Stanbic IBTC, ARM, FBNQuest, Coronation, and Meristem all accept ₦1,000–₦5,000 minimums, redeem within 2–5 working days, and yielded 20–24% in 2025. The discipline lever is the platform's lock; the social warmth can come from a WhatsApp accountability group. The same ₦10,000 monthly that produces ₦120,000 in an Ajo produces about ₦135,000 in an ARM MMF — a 12.7% uplift, every year, forever, with zero counterparty risk.
The bottom line
Ajo is not evil. It is not stupid. It was a brilliant solution to the financial exclusion of an earlier century, and millions of Nigerians have legitimately survived and thrived through it. But the math of Ajo has not changed since Bascom documented it in 1952: internal rate of return zero, aggregate net present value zero, transfer of wealth from late collectors to early collectors, and a real loss of 11–14% per cycle to inflation alone. The first person to pack collects an interest-free loan; the last person to pack has lent everyone else interest-free for a year. In a country where T-bills pay 16%, MMFs pay 21%, and a smartphone is enough to access both, continuing to run a traditional Ajo is paying the price of financial exclusion you no longer suffer. The most loyal thing a Nigerian saver can do for their family is to keep the trust, keep the group, keep the discipline — and move the money into something that actually works for them while they sleep.
