Denomination Effect: Why a Single Bill Is Harder to Spend Than Change

A 5 dollar bill and five singles buy exactly the same things, and people treat them differently anyway. Raghubir and Srivastava's explanation is that a large bill is psychologically less fungible than its equivalent in small change: it reads as one whole thing rather than as five spendable units, and breaking it feels like a decision in a way that handing over a single does not. Small bills go one at a time, almost without noticing; the large bill has to be opened, and the opening is where the hesitation lives.

That hesitation does work for people, and the 2009 paper argues that this is the point. Keeping money in a large denomination is a self-control device. Someone who wants to hold on to 100 dollars has a better chance of doing so with one bill than with five 20s, because every purchase would have to start by breaking the whole. In Study 2 of the paper, when participants read a scenario in which they were behind on a monthly savings goal, most chose to be paid a 100 dollar fee as a single bill; when the goal had already been met, most preferred five 20s, which are easier to spend.

The effect has a second half that cuts the other way. Once the decision to spend has been made, people who break a large bill tend to spend more than people spending small bills, a pattern the authors link to a what-the-hell response: the precommitment has already failed, so the rest of the money is less closely watched. In two of the three field studies the average amount spent by those who did buy was higher in the large denomination condition.

Mishra, Mishra and Nayakankuppam had reported a related finding in 2006, which they called a bias for the whole: people said they would spend less when imagining a sum as one 100 dollar bill than as five 20s. Raghubir and Srivastava moved from stated intentions to actual purchases, showed that the amount spent after the decision runs the other way, and put self-control at the center of the account.

Priya Raghubir and Joydeep Srivastava published "The denomination effect" in the Journal of Consumer Research in December 2009. The paper reports three field studies of real spending, numbered 1a, 1b and 1c, and two scenario studies of the choice between denominations, Studies 2 and 3. The demo on this page reproduces Study 1b, the gas station.

In Study 1a, 89 undergraduate business students at two US universities were thanked for taking part in an experimental session with a dollar, either as a single bill or as four quarters, and told they could keep it or buy candy with it. About 63 percent of the students who held quarters bought candy, 27 of 43; among those who held a bill, 26 percent did, 12 of 46. In Study 1b, 75 adult drivers at a gas station in Omaha answered three questions about gas usage and were paid 5 dollars in one of three forms: five 1 dollar bills, five 1 dollar coins, or one 5 dollar bill. Comparing the two paper conditions, 24 percent of those given five singles made a purchase that was not gas, against 16 percent of those given the single 5 dollar bill. The coin group spent least, 12 percent, which the authors put down to dollar coins being kept as souvenirs. With about 25 people per condition the gas station gap is a handful of shoppers, and the paper rests on the three field studies together.

Study 1c moved the amount up. In Xiangtan, China, 150 women between 25 and 45 were given 100 yuan, as a single note or as a mix of smaller notes, and offered household goods such as soap, shampoo, bedding and cookware at a simulated store. About 91 percent of those with small notes bought something, against 80 percent of those with the single note, and those who did buy spent more on average in the single note condition.

Studies 2 and 3 asked which denomination people would choose to receive. In Study 2, 79 students read a scenario in which they were paid 100 dollars for a focus group, either while running 100 dollars short of a monthly savings goal or after having met it. About 74 percent of those who had met the goal asked for five 20s; among those who were short, only about 22 percent did, and the rest asked for the single 100 dollar bill.

The pattern shows up wherever cash changes hands in different forms. The rows below are illustrations, not findings from the studies cited on this page.

The effect can be put to work as well as corrected; the 2009 paper's participants used large bills on purpose when they wanted to hold on to money.

• When you want to save cash, hold it as the largest bill that is practical. The hesitation before breaking a 100 is the effect doing what you want.
• When you have just broken a large bill, slow down. The money that comes back as change is the same money; the paper found that people who break a large bill tend to spend more once they start.
• Convert small bills and coins into a single sum once in a while, in a count or a bank deposit, so that they are seen as the amount they add up to rather than as loose change.
• Before a purchase paid with small bills, ask whether you would make it if you had to break a 50. If the answer is no, the purchase is being carried by the form of the money.
• Notice when a seller gives change in small bills or offers to break a large one for you. The convenience is real, and so is the effect on how fast the change goes.

Cards and phone payments remove denominations altogether, and with them this particular brake.

The denomination effect is specifically about the physical form of the same amount of money. Its neighbors are about how money is categorized, measured or described.

• It is not mental accounting, the habit of sorting money into separate budgets and treating a dollar differently by which budget it sits in. The denomination effect needs no budgets; the same dollars in the same account are spent differently depending on the bills they come in.
• It is not the money illusion, which is thinking in face values rather than purchasing power, so that a raise that matches inflation feels like a gain. Denomination is about the number of pieces, not the number printed on them.
• It is not unit bias, the tendency to treat one portion or one package as the right amount regardless of its size. The two share the idea that a whole unit resists being divided, but unit bias is about consumption and the denomination effect about spending.