Cognitive BiasesPublic knowledge library

Practice Lab

Comparing plans & pricing

Learn to connect a practical check with the evidence-reviewed lens behind it. A real situation can involve several patterns, so each exercise asks for the best first lens among the listed options, not a diagnosis.

How to use this set

Read the check. Choose a lens. Then inspect the evidence.

Use these evidence-reviewed lenses when comparing subscription tiers, product plans, vendor offers or recommendation menus where the way options are arranged may change what looks attractive.

Read the full decision guide before or after the set.

Exercise 1 of 4

In comparing plans & pricing, which lens does this check belong to: “Does removing the inferior or strategically positioned option change my preference between the remaining plans?”

  1. Decoy Effect
  2. Default Effect
  3. Anchoring Effect
Show the best first lens

Decoy Effect

Does removing the inferior or strategically positioned option change my preference between the remaining plans?

Evidence note The decoy effect is a well-documented family of context effects in which adding an inferior or otherwise strategically positioned alternative can change choice shares among the original options. The classic attraction effect uses an asymmetrically dominated decoy that is worse than the target but not necessarily worse than the competitor. The effect is not guaranteed: its size depends on the geometry of the options, prior preferences, task design and other moderators, and preregistered replications have found both successful and weak or null results.

Read the evidence review · Open the decision guide

Exercise 2 of 4

In comparing plans & pricing, which lens does this check belong to: “Which plan applies if I do nothing, and is that automatic outcome being mistaken for preference?”

  1. Anchoring Effect
  2. Framing Effect
  3. Default Effect
Show the best first lens

Default Effect

Which plan applies if I do nothing, and is that automatic outcome being mistaken for preference?

Evidence note Pre-selecting an option often increases the chance that people choose it, but the size of the default effect varies greatly across domains and designs. A 2019 meta-analysis of 58 studies found a substantial average effect together with strong heterogeneity, including some studies with little or even reversed effects. Staying with a default should therefore not be treated as a direct measure of strong preference or as proof that the default improved welfare.

Read the evidence review · Open the decision guide

Exercise 3 of 4

In comparing plans & pricing, which lens does this check belong to: “Which displayed price, budget or recommendation became the starting point for my value judgment?”

  1. Decoy Effect
  2. Anchoring Effect
  3. Framing Effect
Show the best first lens

Anchoring Effect

Which displayed price, budget or recommendation became the starting point for my value judgment?

Evidence note Anchoring is a well-supported effect in which an initial numerical value can pull a later estimate toward it. A 2026 meta-analysis covering 2,601 effect sizes found a large overall effect, but also substantial variation across studies. The effect should not be treated as a rule that every number changes every judgment: incidental anchors, anchors from a different dimension, clearly random values, incentives, and some debiasing conditions were associated with smaller or null effects.

Read the evidence review · Open the decision guide

Exercise 4 of 4

In comparing plans & pricing, which lens does this check belong to: “Are equivalent features, gains, losses or rates described differently across the options?”

  1. Framing Effect
  2. Decoy Effect
  3. Default Effect
Show the best first lens

Framing Effect

Are equivalent features, gains, losses or rates described differently across the options?

Evidence note Framing research covers several distinct paradigms. Risky-choice framing, where equivalent outcomes are presented as gains or losses, is a well-established effect with substantial evidence across many studies. A classic meta-analysis found a reliable small-to-moderate average effect with strong variation across designs, and later reviews and metastudies support broad generalizability. Attribute framing also has supporting evidence, while goal or message framing is less consistently established. These should not be treated as one identical effect caused by any change in wording.

Read the evidence review · Open the decision guide