[Election-Methods] RE : How to use rankings below approval cut-off

Stéphane Rouillon stephane.rouillon at sympatico.ca
Mon Dec 17 18:45:29 PST 2007

In a single district it would elect A (the straightforward approval winner).
To feed a multiple winner method, it would tell us:
in this district the support for the candidates are A (49), B (48), C (3).
These supports can be used both to produce a proportional result and to 
each political party list from the ballots instead of using an order 
designated by each party chief.

Suppose 9 other districts with results:
2: A(55) B(23) C(22)
3: A(97) B(2) C(1)
4: ...
5: ...
6: ...
10: ...

The average for each party indicates party support that can be 
interpeted as seats. Let's suppose
averages give: A(60) B(30) C(10). For 10 seats these numbers represent 
the perfect proportional share:
A(6) B(3) C(1). And for what is known, candidate for party A in the 
first district as less chances of being elected
than candidate B in the first district because his support is under his 
party average while B's support is above party B average. This method 
suppose equivalent electorate per district, thus many or no candidates 
can be elected for each district.

SPPA is like an improved STV while maximizing both proportionality and 
ballot simplicity (only one name per political party on each ballot).

Supports have to be legitimate, highest support candidates are not 
necessarily winners.

S. Rouillon

Kevin Venzke a écrit :
> Stephane,
> I have some difficulty understanding your method. It looks like you
> repeatedly find the RP(wv) ranking and assign the last-ranked candidate a
> score based on approval (in a way that I didn't totally understand). Then
> you disregard this candidate when redetermining the ranking. So that
> somehow, which candidates are still being considered in the ranking affects
> your approval-based score. If this is basically right then I'd guess the
> method is at least not monotonic.
> What is your answer to Chris' question about the resolution of this
> scenario? :
>> 49: A | > C
>> 48: B | > C
>> 03: C | > B
> He thinks your method elects A. While I can understand why this kind of
> method could elect A, it seems alarming to me that it collects the
> "disapproved" rankings, which not only seem unused, but also draw attention
> to the method's failure of criteria. I imagine it would undermine the
> perceived legitimacy of the winner.
> Kevin Venzke
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