Disclaimer: I wrote this all for myself not to change your mind or argue. Helps if I write down my thoughts and I don’t see a problem sharing. Feel free to discuss if you like.
35 voters: Alice > Carol > Bob
35 voters: Bob > Carol > Alice
30 voters: Carol > Alice > Bob
Vs.
41 voters: Alice > Carol > Bob
29 voters: Bob > Carol > Alice
30 voters: Carol > Alice > Bob
Alice wins
Vs.
Carol wins
Say you have:
41 voters: Republican > Third-party > Democratic
29 voters: Third-party > Democratic > Republican
30 voters: Democratic > Third-party > Republican
If those 29 voters couldn’t vote Third-party they would vote Democratic. So when the Third-party candidate is knocked out, their votes should favor their second pick. Democratic wins 59-41.
If it was:
41 voters: Republican > Third-party > Democratic
29 voters: Third-party > Republican > Democratic
30 voters: Democratic > Third-party > Republican
Which makes more since on why the 6 votes moved to Republican because Republican was their second choice.
Then Republicans win 70-30.
In America you’d have 4 basic senarios
25 voters: Republican > Third-party > Democratic
25 voters: Third-party > Democratic > Republican
25 voters: Third-party > Republican > Democratic
25 voters: Democratic > Third-party > Republican
In RCV, Third-party wins.
Let’s say this
30 voters: Republican > Third-party > Democratic
25 voters: Third-party > Democratic > Republican
20 voters: Third-party > Republican > Democratic
25 voters: Democratic > Third-party > Republican
Third-party still wins
40 voters: Republican > Third-party > Democratic
10 voters: Third-party > Democratic > Republican
10 voters: Third-party > Republican > Democratic
40 voters: Democratic > Third-party > Republican
It would be a tie
45 voters: Republican > Third-party > Democratic
10 voters: Third-party > Democratic > Republican
5 voters: Third-party > Republican > Democratic
40 voters: Democratic > Third-party > Republican
It would still be a tie
45 voters: Republican > Third-party > Democratic
5 voters: Third-party > Democratic > Republican
10 voters: Third-party > Republican > Democratic
40 voters: Democratic > Third-party > Republican
Republicans win
Let’s change it to this:
35 voters: Alice > Carol > Bob
35 voters: Bob > Alice > Carol
30 voters: Carol > Alice > Bob
Vs.
41 voters: Alice > Carol > Bob
29 voters: Bob > Alice > Carol
30 voters: Carol > Alice > Bob
Alice wins
Vs.
Alice wins
They couldn’t make their whole point if you just switched Alice and Carol. And it makes much more sense that someone with Alice second would change it to Alice first.
But when 29 votes still hold Alice as last, it does have some weight.
Something just seems off about it and it’s because they cherry picked a senario that would work for their point.
Alice > Carol > Bob
Alice > Bob > Carol
Bob > Alice > Carol
Bob > Carol > Alice
Carol > Alice > Bob
Carol > Bob > Alice
There are 6 ways to vote and they leave out half of them. Then they make Carol supporters favor Alice as their second choice.
20 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
15 voters: Bob > Alice > Carol
20 voters: Bob > Carol > Alice
20 voters: Carol > Alice > Bob
10 voters: Carol > Bob > Alice
Carol eliminated, +10 Bob +20 Alice. Alice would win.
If 5 voters from Bob > Alice > Carol were moved to Alice > Bob > Carol
20 voters: Alice > Carol > Bob
20 voters: Alice > Bob > Carol
10 voters: Bob > Alice > Carol
20 voters: Bob > Carol > Alice
20 voters: Carol > Alice > Bob
10 voters: Carol > Bob > Alice
Alice would win
What if everyone from Bob > Alice > Carol moved to vote for Alice > Bob > Carol
20 voters: Alice > Carol > Bob
30 voters: Alice > Bob > Carol
0 voters: Bob > Alice > Carol
20 voters: Bob > Carol > Alice
20 voters: Carol > Alice > Bob
10 voters: Carol > Bob > Alice
It would be a tie.
In bold are the three they selected:
20 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
15 voters: Bob > Alice > Carol
20 voters: Bob > Carol > Alice
10 voters: Carol > Alice > Bob
20 voters: Carol > Bob > Alice
5 voters from Bob > Carol > Alice moved to Alice > Carol > Bob. Just like their example.
26 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
15 voters: Bob > Alice > Carol
14 voters: Bob > Carol > Alice
10 voters: Carol > Alice > Bob
20 voters: Carol > Bob > Alice
Alice 41
Bob 28
Carol 30
Bob is eliminated.
15 votes goes to Alice. 14 goes to Carol.
Alice still wins.
But they set it up like:
20 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
0 voters: Bob > Alice > Carol
35 voters: Bob > Carol > Alice
10 voters: Carol > Alice > Bob
20 voters: Carol > Bob > Alice
5 voters from Bob > Carol > Alice moved to Alice > Carol > Bob. Just like their example.
26 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
0 voters: Bob > Alice > Carol
29 voters: Bob > Carol > Alice
10 voters: Carol > Alice > Bob
20 voters: Carol > Bob > Alice
Then when Bob is eliminated all 29 votes go to Carol.
Then they say “It’s unfair that Carol wins”. When in reality those 29 people would prefer Carol over Alice.
RCV might have some flaws but that article has some flaws.
The first article is from someone who wants to save RCV, despite that one flaw that they’ve drilled into.
The problem is that it’s a known attack vector, the Wikipedia article talks about how it was used intentionally by a political party in 2005 in Germany to effectively steal an additional seat in their parliament.
My second link is a deeper dive into more of RCV’s many flaws. Because why stop at monotonicity? Seriously, the fact that increasing support can cause a candidate to lose, and not just lose but elect the worst choice, is insane.
That fact that there are more flaws, just as game breaking, means we should all follow the example of the Marquis de Condorcet, the guy who invented RCV, abandoned it because he saw how broken it was.
The Condorcet criterion is that if you were to hold a series of one on one elections between all candidates, the winner of those should be the same winner of your election system. RCV fails this in most elections, which is why Condorcet abandoned it.
It wasn’t until about 30 years after Condorcet’s death that an Englishman revived the voting method, but added a proportional twist. It still had all the flaws that Condorcet wrote about, but Condorcet was French, and lost the political games of the French Revolution, so he was mostly ignored.
As a side note, the political writings of Condorcet should be required reading. The guy wrote this in 1790
‘The rights of men stem exclusively from the fact that they are sentient beings, capable of acquiring moral ideas and of reasoning upon them. Since women have the same qualities, they necessarily also have the same rights. Either no member of the human race has any true rights, or else they all have the same ones; and anyone who votes against the rights of another, whatever his religion, colour or sex, automatically forfeits his own.’
Interesting… Do you have an example of this?
https://medium.com/@Gbgrow/understanding-non-monotonicity-in-ranked-choice-voting-and-how-to-prevent-it-55ad54fdad06
https://electionscience.org/research-hub/the-limits-of-ranked-choice-voting
https://en.wikipedia.org/wiki/Negative_responsiveness_paradox#Specific_examples
We’ve seen it happen in actual elections, as shown in the Wikipedia link.
RCV is just a flawed system, which is expected for something created by a couple of guys 150+ years ago.
Thanks for the links. I appreciate it! Now I understand the issue.
Disclaimer: I wrote this all for myself not to change your mind or argue. Helps if I write down my thoughts and I don’t see a problem sharing. Feel free to discuss if you like.
35 voters: Alice > Carol > Bob
35 voters: Bob > Carol > Alice
30 voters: Carol > Alice > Bob
Vs.
41 voters: Alice > Carol > Bob
29 voters: Bob > Carol > Alice
30 voters: Carol > Alice > Bob
Alice wins
Vs.
Carol wins
Say you have:
41 voters: Republican > Third-party > Democratic
29 voters: Third-party > Democratic > Republican
30 voters: Democratic > Third-party > Republican
If those 29 voters couldn’t vote Third-party they would vote Democratic. So when the Third-party candidate is knocked out, their votes should favor their second pick. Democratic wins 59-41.
If it was:
41 voters: Republican > Third-party > Democratic
29 voters: Third-party > Republican > Democratic
30 voters: Democratic > Third-party > Republican
Which makes more since on why the 6 votes moved to Republican because Republican was their second choice.
Then Republicans win 70-30.
In America you’d have 4 basic senarios
25 voters: Republican > Third-party > Democratic
25 voters: Third-party > Democratic > Republican
25 voters: Third-party > Republican > Democratic
25 voters: Democratic > Third-party > Republican
In RCV, Third-party wins.
Let’s say this
30 voters: Republican > Third-party > Democratic
25 voters: Third-party > Democratic > Republican
20 voters: Third-party > Republican > Democratic
25 voters: Democratic > Third-party > Republican
Third-party still wins
40 voters: Republican > Third-party > Democratic
10 voters: Third-party > Democratic > Republican
10 voters: Third-party > Republican > Democratic
40 voters: Democratic > Third-party > Republican
It would be a tie
45 voters: Republican > Third-party > Democratic
10 voters: Third-party > Democratic > Republican
5 voters: Third-party > Republican > Democratic
40 voters: Democratic > Third-party > Republican
It would still be a tie
45 voters: Republican > Third-party > Democratic
5 voters: Third-party > Democratic > Republican
10 voters: Third-party > Republican > Democratic
40 voters: Democratic > Third-party > Republican
Republicans win
Let’s change it to this:
35 voters: Alice > Carol > Bob
35 voters: Bob > Alice > Carol
30 voters: Carol > Alice > Bob
Vs.
41 voters: Alice > Carol > Bob
29 voters: Bob > Alice > Carol
30 voters: Carol > Alice > Bob
Alice wins
Vs.
Alice wins
They couldn’t make their whole point if you just switched Alice and Carol. And it makes much more sense that someone with Alice second would change it to Alice first.
But when 29 votes still hold Alice as last, it does have some weight.
Something just seems off about it and it’s because they cherry picked a senario that would work for their point.
Alice > Carol > Bob
Alice > Bob > Carol
Bob > Alice > Carol
Bob > Carol > Alice
Carol > Alice > Bob
Carol > Bob > Alice
There are 6 ways to vote and they leave out half of them. Then they make Carol supporters favor Alice as their second choice.
20 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
15 voters: Bob > Alice > Carol
20 voters: Bob > Carol > Alice
20 voters: Carol > Alice > Bob
10 voters: Carol > Bob > Alice
Carol eliminated, +10 Bob +20 Alice. Alice would win.
If 5 voters from Bob > Alice > Carol were moved to Alice > Bob > Carol
20 voters: Alice > Carol > Bob
20 voters: Alice > Bob > Carol
10 voters: Bob > Alice > Carol
20 voters: Bob > Carol > Alice
20 voters: Carol > Alice > Bob
10 voters: Carol > Bob > Alice
Alice would win
What if everyone from Bob > Alice > Carol moved to vote for Alice > Bob > Carol
20 voters: Alice > Carol > Bob
30 voters: Alice > Bob > Carol
0 voters: Bob > Alice > Carol
20 voters: Bob > Carol > Alice
20 voters: Carol > Alice > Bob
10 voters: Carol > Bob > Alice
It would be a tie.
In bold are the three they selected:
20 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
15 voters: Bob > Alice > Carol
20 voters: Bob > Carol > Alice
10 voters: Carol > Alice > Bob
20 voters: Carol > Bob > Alice
5 voters from Bob > Carol > Alice moved to Alice > Carol > Bob. Just like their example.
26 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
15 voters: Bob > Alice > Carol
14 voters: Bob > Carol > Alice
10 voters: Carol > Alice > Bob
20 voters: Carol > Bob > Alice
Alice 41
Bob 28
Carol 30
Bob is eliminated.
15 votes goes to Alice. 14 goes to Carol.
Alice still wins.
But they set it up like:
20 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
0 voters: Bob > Alice > Carol
35 voters: Bob > Carol > Alice
10 voters: Carol > Alice > Bob
20 voters: Carol > Bob > Alice
5 voters from Bob > Carol > Alice moved to Alice > Carol > Bob. Just like their example.
26 voters: Alice > Carol > Bob
15 voters: Alice > Bob > Carol
0 voters: Bob > Alice > Carol
29 voters: Bob > Carol > Alice
10 voters: Carol > Alice > Bob
20 voters: Carol > Bob > Alice
Then when Bob is eliminated all 29 votes go to Carol.
Then they say “It’s unfair that Carol wins”. When in reality those 29 people would prefer Carol over Alice.
RCV might have some flaws but that article has some flaws.
I haven’t looked at the others. I might later.
Edit:Formatting
The first article is from someone who wants to save RCV, despite that one flaw that they’ve drilled into.
The problem is that it’s a known attack vector, the Wikipedia article talks about how it was used intentionally by a political party in 2005 in Germany to effectively steal an additional seat in their parliament.
My second link is a deeper dive into more of RCV’s many flaws. Because why stop at monotonicity? Seriously, the fact that increasing support can cause a candidate to lose, and not just lose but elect the worst choice, is insane.
That fact that there are more flaws, just as game breaking, means we should all follow the example of the Marquis de Condorcet, the guy who invented RCV, abandoned it because he saw how broken it was.
Then you have the lying liars at FairVote saying that the Condorcet criterion doesn’t matter in elections.
The Condorcet criterion is that if you were to hold a series of one on one elections between all candidates, the winner of those should be the same winner of your election system. RCV fails this in most elections, which is why Condorcet abandoned it.
It wasn’t until about 30 years after Condorcet’s death that an Englishman revived the voting method, but added a proportional twist. It still had all the flaws that Condorcet wrote about, but Condorcet was French, and lost the political games of the French Revolution, so he was mostly ignored.
As a side note, the political writings of Condorcet should be required reading. The guy wrote this in 1790