mccJul 11, 2024

What is your favorite alternative voting system?

[Notes: • If you vote in one poll in this thread please vote in all of them • For a real world example of what I mean by "Multiround runoff" consider the French system]

Condorcet
15.8%
Instant Runoff
48.6%
Approval
23.3%
Multiround runoff
12.3%
Poll ended at .
Show threadmccJul 11, 2024

What is your favorite alternative voting system? (Poll #2)

[Notes: • If you vote in one poll in this thread please vote in all of them • For a real world example of what I mean by "Multiround runoff" consider the French system]

Condorcet
21.1%
Instant Runoff
39.2%
Approval
20.6%
Multiround runoff
19.1%
Poll ended at .
Show threadmccJul 12, 2024

What is your favorite alternative voting system? (Poll #3)

("Instant Runoff Voting" is when you rank your choices and a multiround runoff is simulated by bumping off candidates one by one and redistributing their votes. "Approval voting" is when you get checkboxes by each candidate and can select more than one; whoever gets the most "approvals" wins.)

Instant Runoff
73.3%
Approval
26.7%
Poll ended at .
Show threadNeia masks
@mcc I'm just hoping we get to implement Dodgson's Method some day.
Jul 12, 2024 at 9:41pmWeb
Show threadmccJul 12, 2024
@neia Do you know how this differs from the "Cloneproof Schwartz" method?
Show threadNeia masksJul 13, 2024
@mcc Do you mean Schulze? It's been a hot minute since I looked into it in detail, but IIRC Schulze is basically looking at how much Candidate A could beat someone who could beat Candidate C and vice versa, and it uses that to resolve cycles where A beats B beats C beats A.

Dodgson's Method alters individual ballots, switching the minimum number of individual preferences to produce a Condorcet winner.

In terms of how well they perform, performance is the biggest one. Schulze is O(n³) in the number of candidates. Dodgson is exponential in the number of ballots. Worse, Dodgson is not in NP. So if a large country like Liechtenstein decided to use Dodgson, they might have to wait a few centuries to get the result of a national election. And if you need independent verification, it will take centuries longer.

For pretty much all other standard voting criteria, Dodgson fails. Like, it fails the anti-Condorcet criterion: if you held a bunch of 1v1 elections and one person lost against every other candidate, Dodgson sometimes elects that one person.