Tactical voting: Difference between revisions
Condorcet strategy result: added methods of each category.
(Added pairwise-only Condorcet strategic susceptibility result.) |
(Condorcet strategy result: added methods of each category.) |
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Due to the especially deep impact of tactical voting in [[first past the post]] electoral systems, some argue that systems with three or more strong or persistent parties become in effect forms of [[disapproval voting]], where the expression of disapproval, to keep an opponent out of office overwhelms the expression of approval, to approve a desirable candidate. [[Ralph Nader]] refers to this as the "least worst" choice, and argues that the similarity of parties and the candidates grows stronger due to the need to avoid this disapproval.
Sirin Botan et al. showed that every Condorcet method of a particular type sometimes incentivizes the creation of Condorcet cycles when there's a sincere [[Condorcet winner]]. The types covered are Condorcet methods that only use pairwise defeat information and don't always tie when there's no Condorcet winner. <ref name="Botan Endriss 2021 pp. 5202–5210">{{cite journal | last=Botan | first=Sirin | last2=Endriss | first2=Ulle | title=Preserving Condorcet Winners under Strategic Manipulation | journal=Proceedings of the AAAI Conference on Artificial Intelligence | publisher=Association for the Advancement of Artificial Intelligence (AAAI) | volume=35 | issue=6 | date=2021-05-18 | issn=2374-3468 | doi=10.1609/aaai.v35i6.16657 | pages=5202–5210}}</ref> This category includes, among others, [[ranked pairs]] and [[Copeland's method]], but not [[Smith//IRV]] or [[Condorcet-cardinal hybrid methods]].
There are arguments about the best voting strategy to take in different systems, but the general consensus is:
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