4,193
edits
Gibbard-Satterthwaite theorem: Difference between revisions
Fixing link to w:Gibbard–Satterthwaite theorem, adding link to old English Wikipedia version (oldid=13601023), and noting that this theorem is derived from It is derived from Arrow's impossibility theorem and Gibbard's theorem (and is not merely "related")
imported>WikipediaBot m (importing text from Wikipedia) |
(Fixing link to w:Gibbard–Satterthwaite theorem, adding link to old English Wikipedia version (oldid=13601023), and noting that this theorem is derived from It is derived from Arrow's impossibility theorem and Gibbard's theorem (and is not merely "related")) |
||
| (6 intermediate revisions by 4 users not shown) | |||
Line 1:
{{Wikipedia}}
In [[voting system]]s, the '''Gibbard-Satterthwaite theorem''' states that every unimposing [[voting method]] (one in which every preference order is achievable) which chooses between three or more candidates, must be either dictatorial or manipulable (i.e. susceptible to [[tactical voting]]). It follows from [[Arrow's impossibility theorem]].▼
▲
[[Category:Voting theory]]▼
==Statement==
For every voting rule, one of the following three things must hold:
# The rule is dictatorial, i.e. there exists a distinguished voter who can choose the winner
# The rule limits the possible outcomes to only two alternatives
# The rule is susceptible to [[strategic voting]]: some voter's sincere ballot may not defend their opinion best.
==Further Reading==
* https://www.rangevoting.org/GibbSat.html
▲[[Category:Voting theory]]
[[Category:Voting system criteria]]
{{fromwikipedia|Gibbard–Satterthwaite theorem|oldid=13601023}}
| |||