[EM] Absolutely new here

[Benjamin Grant]

I just started trying to wrap my brain around all the ins and outs about
voting methods, and I wanted to check two things with my elders (on this
subject):

 

1)      As far as I can see, the reason IRV has some strange/unusual results
is because it is absolutely critical what order you eliminate candidates. So
an election where Voting Bloc 1 has a 13% share of the ballots and Voting
Bloc 2 has a 16% share of the ballots can utterly flip around using IRV if
VB1 goes up two points and VB2 goes down 2. Because with IRV, the order of
elimination is really the first-most deciding factor in who wins.  For
example, here are three different scenarios:

 

40%        A             B             D             C

25           C             B             D             A

20           D             B             C             A

15           B             A             C             D

                WINNER: A                                         

 

(the topline means of course that 40% put candidate A first, B second, D
third, and C last.)

 

40%        A             B             D             C

25           C             B             D             A

26           D             B             C             A

9              B             A             C             D

                WINNER: D                                         

 

40%        A             B             D             C

25           C             B             D             A

17           D             B             C             A

18           B             A             C             D

                WINNER: B                                          

 

A few percent either way on the last line changes *everything*.

 

This seems to be a flaw with IRV, yes? It is "too sensitive" on small
changes because they can change the order of elimination.

 

2)      I haven't seen a voting system like this - what are the issues with
it? Upsides and downsides?

 

A)     Each voter ranks their choices on their ballots, first through last
place.

B)      If one candidate got a majority of 1st place votes, they win. If
not, the second place votes are added. If still no majority he third place
votes are added, and so on, until one candidate has a majority.

 

Would the above system work?

 

Thanks, very new to all these considerations, still trying to learn the
names of the different methods as well as the names and meaning of the
different criteria like Condorcet, Later No Harm, etc.

 

-Benn Grant

eFix Computer Consulting

 <mailto:benn at 4efix.com> benn at 4efix.com

603.283.6601

 

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