[EM] Sincere Condorcet Cycles

[seppley at alumni.caltech.edu]

One thing you might want to keep in mind is that the candidates and the
positions they take on issues are unlikely to be exogenous (given by
nature.) Candidates who want to win tend to take positions that will help
them win. Potential candidates deciding whether to compete may choose not
to in order to avoid being spoilers. Parties nominate only one candidate
per office to avoid spoiling.

Those effects will depend on the voting method. Thus the chance of a
sincere majority cycle will depend on the voting method. With voting
methods with minimal spoiling that induce candidates who want to win to
take similar positions (at the medians) the chance of a sincere cycle will
be much higher than with methods like plurality rule.

Regards,
Steve
-------------------
On Dec 15 2009 robert bristow-johnson wrote:
> On Dec 15, 2009, at 3:49 PM, Juho wrote:
>> On Dec 14, 2009, at 7:11 PM, Kristofer Munsterhjelm wrote:
>>> robert bristow-johnson wrote:
>>>> On Dec 14, 2009, at 12:06 AM, Dan Bishop wrote:
>>>>> robert bristow-johnson wrote:
>>>>>> On Dec 13, 2009, at 7:53 PM, fsimmons at pcc.edu wrote:
>>>>>>> Here's a natural scenario that yields an exact Condorcet Tie:
>>>>>>>
>>>>>>> A together with 39 supporters at the point (0,2)
>>>>>>> B together with 19 supporters at (0,0)
>>>>>>> C together with 19 supporters at (1,0)
>>>>>>> D together with 19 supporters at (4,2)
>>>>>>>
>>>>>>> D is a Condorcet loser.
>>>>>>> A beats B beats C beats A, 60 to 40 in every case.
-snip-