A cognitive bias in which adding a third option (the decoy) that is asymmetrically dominated — worse than one option but not the other — shifts preference toward the option that dominates the decoy. The decoy is designed by choice architects to make a target option appear superior by comparison, even though it was not objectively improved. Parameters: requires a choice set of at least three options with asymmetric dominance. Persistence mechanism: reproduced in laboratory experiments and deployed in commercial pricing strategies across markets. [formal: decoy effect | substrate: mind | horizon: a moment | explicit: yes | epoch: 0.98]
Accepted ontology entry
decoy-effect
A cognitive bias in which adding a third option (the decoy) that is asymmetrically dominated — worse than one option but not the other — shifts preference toward the option that dominates the decoy. The decoy is designed by choice architec…
Definition
Why it is in scope
A human-made cognitive bias where the introduction of a third, asymmetrically dominated option changes a person's preference between two existing options. The decoy is designed so that one option dominates it while being dominated by the other — making the dominating option look more attractive by comparison. Created by behavioral economists Tversky and Kahneman to model preference reversal in choice architecture.
Names and aliases
- decoy-effecten · CANONICAL
Relations from this entry
- cmrvhte03017l2ceiczloqqfhDEPENDS_ON →
Removal test: remove comparison — does decoy-effect stop operating? Yes. The decoy effect operates by making one option look more attractive through comparison with a dominated decoy option. Without the mechanism of comparison between options, the decoy has no effect. The phenomenon is entirely defined by how comparison shifts preference.
- cmrmwufxy01pxd1nllvxs1o1sINSTANCE_OF →
Decoy-effect IS a specific kind of cognitive bias: the tendency for people to change their preference between two options when a third asymmetrically-dominant option (the decoy) is introduced. A competent speaker would say 'decoy effect is a cognitive bias.' Direction specific→general, Law 9.
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Jul 23, 2026, 5:02 PM UTC
- Content hash
- d0a1f53099aa82f8552a3b0d729f2ed47c561ac3c307c8dc5edb7156bf1b70b0