[EM] divided house problem of close vote (50%+1)

Juho juho4880 at yahoo.co.uk
Wed Mar 14 22:19:04 PDT 2007


On Mar 14, 2007, at 12:15 , raphfrk at netscape.net wrote:

> Doubtless this won't thread correctly.
>
> Juho said
> > Some observations.
> >
> > The description talks only about the "yes" votes. Is the assumption
> > that the "no" votes mean "no action will be taken"?
> >
> > If we are talking about approving a new law then this is quite
> > typical, but if we vote for example about whether we should send our
> > rocket to Mars or Venus, then both sides should be treated in the
> > same way.
> >
> > In the described method repeated 45% yes, 55% no results do not lead
> > to final "no" (assuming super majority and new referendum levels  
> 60%/
> > 40%). If we have only one rocket to send, voting first on sending  
> the
> > rocket to Mars, then on sending it to Venus, then to Mars etc. is  
> not
> > fair either. But maybe the method is not intended for this kind of
> > elections with two similar alternatives to choose from.
> >
>
> I get the impression the vote would go something like:
>
> Initial scores = 0
>
> Round 1
>
> Mars: 45%  +0 = 45 (-50 = -5)
> Venus: 55% +0 = 55 (-50 = +5)
>
> Round 2
> Mars: 45%  -5 = 40 (-50 = -10)
> Venus: 55% +5 = 60 (-50 = +10)
>
> Round 3
> Mars: 45%  -10= 35 (-50 = -15)
> Venus: 55% +10= 65 (-50 = +15)
>
> Round 4
> Mars: 45%  -15= 30 (-50 = -15)
> Venus: 55% +15= 70 (-50 = +15)
>
> Venus wins as >2/3

Yes. You seem to assume that the Mars and Venus votes would take  
place more or less simultaneously.

Howard Swerdfeger's xls sheet btw doesn't behave exactly the same way  
as the written description of the method says. It doesn't let the  
Mars results drop below 45%. Thanks to Howard Swerdfeger for  
providing the sheet. Tthat is a good method to give clear  
(operational) definitions to the methods.

Note that it is possible that the sum of Mars and Venus votes need  
not be 100%. It is possible for example to have a faction that is  
eager to send a rocket to any planet. As a result both planets may  
get !50% results. In this case I don't know what happens if both  
planets reach the super majority limit at the same round.

One could also make the rules such that there is only one Mars vs.  
Venus vote at each round and the decision will be made when the  
balance will go from 50% to some threshold % to either direction.  
This way the election would be a symmetric election between two  
similar options (not a status quo vs. change type of election as in  
the original version).

> This means that a majority can get anything past if they stick to  
> their
> guns, however, it will take lots of votes (spaced say 1 day apart).
>
> It also naturally scales the time spent debating based on how
> controversial the decision is.
>
> Handling multiple choices could be handled with approval voting.   
> Using
> multiple rounds means that the tactics for approval are easier to use.

Yes. Even Condorcet could be used - just keep increasing/decreasing  
the elements of the comparison matrix.

I think there could be also electronic election methods where results  
are calculated in real-time and voters may change their vote when  
they see what the current results are. The behaviour of a method in  
this situation could be also used as one criterion to evaluate the  
stability of the method. This kind of situations could make also the  
Nash equilibrium of strategic voting states more meaningful (I have  
earlier criticized them as not being a good measure for typical ("non  
real-time feedback") elections).

Juho


> For example, if you could use the following formula
>
> New Approval = 2/3 * ( Old Approval*3/4 + approval from vote )
>
> if 50% approve of an option, it will get
>
> Round 1:
> 2/3*( 0 + 50) = 33%
>
> Round 2:
> 2/3*(25+50) = 50%
>
> Round 3:
> 2/3*(38+50) = 59%
>
> Round 4:
>
> 2/3*(44+50) = 63
>
> At round N (with N -> inf)
>
> Round N
>
> 2/3*(50+50) = 66 and 2/3
>
> Round N+1
>
> 2/3*(50+50) = 66 and 2/3
>
> I would suggest rounding upwards to the nearest percent.  Ignoring  
> rounding
> an option cannot get the supermajority unless it has 50%+ approval.
>
>
> Alternatively, rounding down could be used and the supermajority  
> could be
> set to say 65% required.
>
>
>
> Raphfrk
> --------------------
> Interesting site
> "what if anyone could modify the laws"
>
> www.wikocracy.com
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