Decoy effect
Claim assessed: A third option, clearly worse than one of the main ones, makes that one get chosen more often.
Published · how we work
In short
The decoy effect, also called the attraction effect, appears when you choose between two options that trade off: one is better but pricier, the other cheaper but weaker. If a third option is added that is clearly worse than one of them, but not than the other, the option that beats it gets chosen more often. The third option is the decoy. The effect is solid in experiments with numbers, but much weaker or absent with real products.
What it says
The original study. Huber, Payne and Puto (1982) set out to test a rule of rational choice theory: adding an option can’t make an existing option get chosen more often. They built decoys that almost nobody chose, about 2% of participants on average, and showed that the rule can be broken. We haven’t read the study; we describe it from the authors’ 2014 reply.
The limits. Frederick, Lee and Baskin (2014) noticed that almost all demonstrations described products only by numbers, for example a TV with picture quality 7.3 and a price of 390 dollars. In 19 studies with products that were tasted, touched or seen, from drinks and fruit to photos of apartment views, they never found the effect. Sometimes the decoy even reduced the choice of the option it was meant to help. With gambles, the effect appeared when the chance of winning was written as a percentage, but disappeared when the same chance was drawn as a slice of a circle. They also failed to replicate several famous studies, among them an example with subscriptions to a publication, popularised in a bestselling book.
The original authors’ reply. Huber, Payne and Puto (2014) answered that the effect replicates when the study’s conditions are reproduced, as the numeric gambles showed. They explained why the effect can disappear: people already have clear preferences, don’t notice that the decoy is worse, or even choose the decoy. In some of the criticised studies, up to 18% of participants chose the decoy. They acknowledged, though, that in its strict form the effect probably occurs rarely in the marketplace, where products have many attributes and clearly inferior options don’t last long on the shelf.
A large preregistered test. Hasan et al. (2025) tested the effect on 2,293 people, with over 22,000 choices between products such as apartments, laptops or paper towels. They varied how the options were presented: numbers or bar charts, their order and their layout. The effect appeared in 23 of 24 variants: the option helped by the decoy was chosen on average 1.5 times as often as the other. It was slightly weaker with charts than with numbers and weaker when the decoy wasn’t next to the option it helped. In every variant, though, the attributes were given explicitly.
Real purchases. Devine et al. (2025) analysed 3.6 million wine purchases from a UK supermarket chain. They compared pairs of popular wines, one better and pricier, the other cheaper and weaker, with quality estimated from ratings in the Vivino app. When the other wines on the shelf were, on average, pricier and weaker than one of the two, that wine was chosen slightly more often. The difference was about 1%. Among people who bought wine often, the effect almost disappeared.
Example
A cinema sells small popcorn for 10 lei and large for 18 lei. If it adds a medium portion, also for 18 lei but smaller than the large one, the large portion may look like a good deal. The example is an illustration, not a study cited here.
How to apply it
The steps below are a practical way to apply it that we propose, based on the studies cited.
- Set aside the clearly worse option. Then compare only the two options that trade off.
- Ask whether you’d choose the same without the third option. That is exactly the rule the decoy breaks.
- Decide in advance what matters to you. Huber et al. note that the effect shrinks when people already have clear preferences, and Devine et al. found it almost absent among frequent buyers.
- Don’t rely on decoys as a sales trick. In real wine purchases the effect was about 1%, and with products tried directly it didn’t appear.
Limits and nuances
- The effect depends heavily on presentation. It is stronger with numbers, with the options side by side and with the products used in older studies.
- The two camps agree on the facts, not on the conclusion. Frederick et al. question the effect’s practical usefulness; Huber et al. consider that the effect shows something important: preferences are constructed at the moment of choice.
- The wine study is correlational. The authors inferred which wines were on the shelf from what was bought on the same day in the same store, so the customers’ real choice sets are approximated.
- The preregistered test ran online, on a paid survey platform. The choices were hypothetical, and the attributes were always given explicitly, not tried.
- We excluded Dan Ariely’s work. He co-authored a 2012 study retracted in 2021, after the data of a field experiment he supervised were shown to be fabricated; who fabricated them can’t be told from the data. The subscription example, also featured in his book Predictably Irrational, is mentioned only as a result that didn’t replicate.
- What we read. Frederick et al. (2014), from the Columbia University repository, Huber et al. (2014), from a Duke author’s page, Hasan et al. (2025) and Devine et al. (2025), both open access, we read in full. We haven’t read Huber et al. (1982); we describe it from the 2014 reply.
Sources
- Joel Huber, John W. Payne, Christopher Puto (1982). Adding asymmetrically dominated alternatives: Violations of regularity and the similarity hypothesis
- Shane Frederick, Leonard Lee, Ernest Baskin (2014). The limits of attraction
- Joel Huber, John W. Payne, Christopher P. Puto (2014). Let's be honest about the attraction effect
- Eeshan Hasan, Yanjun Liu, Nicole Owens, Jennifer S. Trueblood (2025). A registered report on presentation factors that influence the attraction effect
- Sean Devine, James Goulding, John Harvey, Anya Skatova, A. Ross Otto (2025). How decoy options ferment choice biases in real-world consumer decision-making
See also: Anchoring, Default effect, Framing effect