── ── Cognitive bias
Endowment Effect
People demand roughly 2× more to give up something they own than they would pay to acquire the identical thing — purely because they own it. Ownership converts a transaction from a potential gain into a potential loss, and losses loom ~2× larger than gains (prospect theory). The effect kicks in within 30 seconds of possession; customization and personalization amplify…
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How it works
markdown S1 — Ownership: who owns it · what · how long · customization level S2 — Gap: owner's value · market ref · gap $% · external comps S3 — Attribute gap: info asymmetry % · legitimate features % · endowment % · loss-framing language? S4 — Direction: Leverage: what triggers buyer endowment? (trial length, personalization depth) · ethical? Counteract: neutral reference price? · earnout possible? · framing ("exchange" not "sale") S5 — Bridge: deal structure · earnout milestones · reference anchor · framing adjustments S6 — Close: endowment premium isolated? · bridge tested vs seller loss threshold? · ethical check · decision
When to use it
- seller is asking way more than buyers will pay
- a founder or homeowner insists their asset is worth far more than market comps
- a team refuses to cut a feature they built
- a free-trial cancellation flow has more friction than signup
- someone says 'I've put too much into this to sell for that.'
When not to use it
the valuation gap is explained by genuine information asymmetry the seller actually has; the asset is a pure commodity with a transparent live market price (endowment effect is weak when reference prices are salient).
Worked example
The In-House Model Trap and Founder Valuation in the AI Cycle (2023–2026)
The 2023–2026 generative-AI boom created two textbook endowment-effect situations that recurred across the industry:
Install this skill (free, MIT)
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Related mental models
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