[EM] How choice of voting systems depend on amount of participants

[Juho Laatu]

On 07 Oct 2014, at 02:50, Richard Fobes <ElectionMethods at VoteFair.org> wrote:

> On 10/6/2014 4:10 PM, dikov dikov wrote:
> > I though that Condorcet methods are better when multiple places are
> > concerned. Then scoring every entry brings relevant ranking. On another
> > hand if only one winner is considered than simple majority system is
> > accurate enough.
> > Is it correct, or I am wrong?
> 
> I'm not sure what you mean by "if only one winner is considered," but I'd say that your interpretation is not yet correct.
> 
> The biggest issue is the number of candidates.  That is true regardless of the number of winners.
> 
> The only way that simple majority ("plurality") voting works is if there are only two candidates.  It also works if one of the candidates gets a majority (more than half) the votes, but most people mistakenly think that that means the winner can be whichever candidate gets the most votes.  (Most votes and more than half the votes are very different.)
> 
> If there are three or more candidates -- which many of us believe should be the case in any governmental election -- then single-mark ballots (where only one candidate name can be marked) do NOT work.

Just a short note. There are also two round elections that use "single-mark ballots" and that work reasonably well (at least better than pluraliy) also with multiple candidates.

BR, Juho


> 
> In these cases (most real elections), there are three kinds of ballots to choose from:
> 
> *  Approval ballots, where more than one candidate name can be marked.
> 
> *  Ranked ballots, also called 1-2-3 ballots, (and sometimes other names are used), which you recognize.
> 
> *  Score ballots, where each candidate is given a score, similar to Amazon's use of 1 to 5 stars.
> 
> Condorcet voting methods use ranked ballots.
> 
> If approval ballots or score ballots are used, then whichever candidate gets the most "votes" (approvals or points) wins.
> 
> For more details, and a more careful explanation, please take a look at this web page:
> 
>  http://www.bansinglemarkballots.org/declaration.html
> 
> It is the "Declaration of Election-Method Reform Advocates" that most of us who are active here on this forum (with a few exceptions) collectively wrote and signed.
> 
> I figure that as long as you need to ask questions then there may be other people reading this forum who also have the same, or similar, confusions, so keep asking questions if you need clarity about any details.
> 
> Richard Fobes
> 
> 
> On 10/6/2014 4:10 PM, dikov dikov wrote:
>> Hi,
>> 
>> Thank you for the reply and sorry for the pause.
>> 
>> I though that Condorcet methods are better when multiple places are
>> concerned. Then scoring every entry brings relevant ranking. On another
>> hand if only one winner is considered than simple majority system is
>> accurate enough.
>> Is it correct, or I am wrong?
>> 
>> Thank you,
>> 
>> DMytro
>> 
>> 
>> 
>> 
>> 
>> On Tuesday, September 30, 2014 12:37 PM, Juho Laatu
>> <juho4880 at yahoo.co.uk> wrote:
>> 
>> 
>> On 30 Sep 2014, at 07:10, dikov dikov <dikov1 at yahoo.com
>> <mailto:dikov1 at yahoo.com>> wrote:
>> 
>> 
>>> So if a contest assumes only one winner than any method is valid, right?
>>> 
>> 
>> There age good and bad methods. In this list (that is quite good) many
>> people could recommend e.g. some Condorcet methods.
>> 
>> I brief, Condorcet methods are very good at least in a situation where
>> - you elect one winner
>> - the elecion is competitive (i.e. people try to vote so that one of
>> their favourites will win)
>> - you can afford the complexity of a method where the voters will rank
>> the candidates (or at least some of them) in their preference order
>> 
>> (If you elect multiple winners, if the elction is not competitive (e.g.
>> _neutral_ judges elect their favourite athlete) or if you need a simpler
>> method, then it could be better to use some other methods.)
>> 
>> I write this just to make a long story short. Many (maybe most) people
>> on this list (not all) think that Condorcet methods are good general
>> purpose sigle-winner methods for competitive elections.
>> 
>> BR, Juho
> 
> 
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