The decoy effect

Also known as the asymmetric dominance effect · Decision-making

The decoy effect is when adding a third, deliberately inferior option changes which of the original two you prefer. The "decoy" isn’t meant to be chosen — it’s there to make one option look like obviously better value.

By the ReadGlobe Editors · Reviewed 2026-05-29

Why it happens

We judge value by comparison, not in absolute terms. A decoy that’s clearly worse than one option (but not the other) makes that option "dominate," nudging us toward it.


Your preferences aren't fixed — change the menu and you change the mind without changing the options.

Examples

  • The Economist’s pricing: a print-only option priced the same as print+web made print+web the "obvious" deal.
  • Small popcorn $4, large $7, medium $6.50 — the medium decoy sells the large.
  • Three-tier SaaS pricing where the middle tier exists mainly to sell the top one.

How to counter it


  • Ignore options you’d never pick — don’t let a decoy frame the others.
  • Evaluate each option against your needs, not against the other options.
  • Ask whether the "great deal" only looks great next to a planted dud.

The deeper point

It’s proof your preferences aren’t fixed — they’re constructed at the moment of choosing, from whatever’s on the table. Change the menu and you change the person’s mind without changing the options they actually want.

Frequently asked


What is the decoy effect?
When adding a deliberately inferior third option changes your preference between the original two — the decoy exists to make one option look like clearly better value.
What is the Economist pricing example?
Offering print-only at the same price as print+digital made the combined option seem an obvious deal; the print-only "decoy" sharply boosted sales of the bundle.
How do you avoid the decoy effect?
Judge each option against your own needs rather than against the others, and ignore any option you’d never realistically choose.

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APA

ReadGlobe. (2026). The decoy effect. https://readglobe.com/bias/decoy-effect/

MLA

"The decoy effect." ReadGlobe, 29 May 2026, readglobe.com/bias/decoy-effect/.

Primary source: Wikipedia

Editorial synthesis © ReadGlobe 2026, drawing on Kahneman’s Thinking, Fast and Slow, the Tversky–Kahneman research program, and the primary cognitive-science literature. · Last reviewed 2026-05-29.