Word.ws English Dictionary

Gibbard's theorem

Gibbard's theorem proper noun: a theorem stating that, for any deterministic process of collective decision, at least one of the following three properties must hold: (i) the process is dictatorial, i.e. there exists a distinguished agent who can impose the outcome; (ii) the process limits the possible outcomes to two options only; (iii) the process encourages agents to think strategically: once an agent has identified their preferences, they have no action at their disposal that would best defend their opinions in any situation.

Proper noun

Gibbard's theorem

  1. A theorem stating that, for any deterministic process of collective decision, at least one of the following three properties must hold: (i) the process is dictatorial, i.e. there exists a distinguished agent who can impose the outcome; (ii) the process limits the possible outcomes to two options only; (iii) the process encourages agents to think strategically: once an agent has identified their preferences, they have no action at their disposal that would best defend their opinions in any situation.

Origin of Gibbard's theorem

Proven by philosopher Allan Gibbard in 1973.

Questions about Gibbard's theorem

What does Gibbard's theorem mean?
Gibbard's theorem means a theorem stating that, for any deterministic process of collective decision, at least one of the following three properties must hold: (i) the process is dictatorial, i.e. there exists a distinguished agent who can impose the outcome; (ii) the process limits the possible outcomes to two options only; (iii) the process encourages agents to think strategically: once an agent has identified their preferences, they have no action at their disposal that would best defend their opinions in any situation.
What part of speech is Gibbard's theorem?
Gibbard's theorem is a proper noun.

Words near Gibbard's theorem in the dictionary

  1. gibanica
  2. gibaro
  3. gibaros
  4. Gibb
  5. gibbable
  6. Gibbard's theorem
  7. Gibbard-Satterthwaite theorem
  8. gibbed
  9. gibbed lathe
  10. gibbed lathes
  11. Gibbens

Source and license

Adapted from Wiktionary: Gibbard's theorem (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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