── ── 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…

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.'

Worked example

Kahneman, Knetsch & Thaler 1990 — The Cornell Mug Experiment

Richard Thaler (1945–; Nobel Laureate in Economics 2017) had identified the endowment effect as a theoretical construct in his 1980 paper mapping departures from standard consumer theory. The empirical proof came from a collaboration with Daniel Kahneman and Jack Knetsch in a series of experiments run at Cornell University in the late 1980s.