Scarcity Error

We attribute more value to things simply because they are rare or becoming scarce — independent of any real change in their usefulness or quality.

• The last cookie in a jar is judged tastier than an identical cookie from a full jar.
• 'Limited edition' and 'only 3 left in stock' labels reliably increase purchase rates — the scarcity is often manufactured.
• A romantic partner becomes dramatically more attractive the moment someone else expresses interest — scarcity increases perceived value.