Ranked Robin: Difference between revisions
Rewrite clone independence note to reflect Talk paragraph as it seems okay
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=== A note on cloneproofness ===
Ranked Robin can fail clone independence in one of two ways: either by its Copeland component or by its Borda component.
The Copeland component fails clone independence by [[w:Independence of clones criterion#Copeland|crowding and teaming]]. It can be argued that a party stands nothing to gain (or lose) by running clones as far as the crowding vulnerability is concerned, because all a candidate A can achieve by triggering a clone failure is to change the candidate from some B to some other C, which doesn't help A since A lost anyway -- unless C just happens to be closer aligned with A's position than does B. However, the teaming incentive may be more conventionally exploitable, since it directly benefits a candidate who runs clones.
The Borda component fails clone independence by teaming. If the [[Copeland set]] consists of more than one candidate, as can happen with some Condorcet cycles, then this could expose the Borda component and allow teaming to succeed. For instance, consider this pre-cloning election:
{{ballots|
12: A>B>C>D>E>F
11: B>C>A>D>E>F
10: C>A>B>D>E>F
}}
The Copeland set is {A,B,C}. A and B tie for Borda score, but this can be shifted in favor of A by teaming, e.g.
{{ballots|
12: A1>A2>B>C>D>E>F
11: B>C>A1>A2>D>E>F
10: C>A1>A2>B>D>E>F
}}
after which A wins.
Ranked Robin passes vote-splitting clone independence: cloning a candidate can't make that candidate lose.
== External links ==
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