[EM] Why I Think Sincere Cycles are Extremely Unlikely in Practice

[Kristofer Munsterhjelm]

robert bristow-johnson wrote:
> 
> On Nov 12, 2010, at 3:57 PM, Juho wrote:
> 
>> Sincere cycles are probably not very common in real elections. There 
>> have already been many ranked ballot based elections with reasonably 
>> sincere ballots, but at least I'm not aware of any top level cycles in 
>> them.
> 
> i haven't examined other jurisdictions running STV (or "IRV" or "RCV" or 
> whatever you draw from the alphabet soup), but the two elections we had 
> in Burlington VT (in 2006 and 2008) using IRV indicated no cycle at any 
> level.  there was a clear CW and then if you remove that candidate from 
> the race, there was another clear CW with the remaining candidates (who 
> i would call the runner-up), and again if you removed that 2nd-placer.  
> both elections were perfectly ordered in a Condorcet fashion from the CW 
> to the CL.  the only remarkable note was that in 2009, the CW didn't 
> make it to the IRV final round which is the only way for IRV to elect 
> someone other than the CW.  in 2006 the CW, IRV winner, and plurality 
> winner were all the same candidate and in 2009, they were three 
> different people.
> 
> i doubt that Condorcet cycles would be common if used in political 
> elections because for the issues that matter the most and that motivate 
> voters the most, it's a pretty clear spectrum from "left" to "right".  
> relatively, just not very many Nader voters would choose Bush over Gore 
> nor many Bush voters would choose Nader over Gore.

Plurality encourages a simple us-versus-them type of campaign since each 
voter only has a first place vote. On the other hand, Condorcet lets 
voters rank parties or candidates in any position, and the candidates 
may benefit from being second of a lot rather than first of most. 
Therefore, it would support a more detailed political space. If that is 
the case, more than just the left-right spectrum could become of 
importance to the voters - for instance, one might get not just 
left-vs-right but local-vs-centralized. If the voters then judge 
according to multiple axes, the chances of a cycle increase.

Do you think that is likely? It would be an effect that would show up 
*after* Condorcet because the other methods can't reliably support such 
a detailed political space. It might also require changes in how the 
legislature is elected, as well, or otherwise the lack of variety there 
would overpower the variety among single-winner candidates.