Mental Accounting

Yes. When petrol prices rose, households switched to cheaper fuel almost 20 times more than an equal loss of income would explain, and a cash transfer in Morocco labelled for education cut school dropout by about three quarters. A 2025 replication supported 11 of 17 classic problems, though a few, such as the calculator problem, did not hold.

What the report found

1. The core idea holds up in the field. When petrol prices rose, households in one large study switched to cheaper fuel almost 20 times more than an equal loss of income from elsewhere would explain. Money earmarked for food was spent on food far more than the same amount of cash.
2. Labels change spending. A cash transfer in Morocco, paid without conditions but labelled for education, cut school dropout by about three quarters. Labelling remittances for education raised the amounts migrants sent.
3. Where money comes from matters. Windfalls, coupons, gift cards and money called a bonus are spent more freely than income or refunds.
4. Not every classic survives. A 2025 replication of 17 problems from Thaler's 1999 review found support for 11, mixed support for 3 and none for 3, including the well known problem of travelling to save on a calculator.
5. Mental accounts are a tool as well as a bias. The same habit that bends spending also helps people save: earmarking money and dividing it between separate accounts raised saving among low income households. The question is less how to remove mental accounting than how to put it to good use.

What is inside

1. The idea and where it came from
2. The original studies, explained
3. What happened when others tested it
4. Where researchers disagree
5. What we can say with confidence

Plus a timeline of the key studies, two debates set out side by side, a summary of the main studies and a table grading each common claim.

Who it is for

For anyone who manages a household budget, sends money home, designs savings, payments or rewards products, or runs programmes that support families.

How we work

Evidence Reviews follow one well known idea from its origin to today: the original studies, what happened when others tested them, where researchers disagree and what we can say with confidence. Every claim is graded, and both sides of each debate are set out before we say where we stand.

Cite this report

The Why We Project (2026) Mental Accounting: Why a dirham is not always a dirham. Evidence Review No. 14. Dubai: Why We Tech Ltd. Available at: thewhyweproject.com