[EM] Condorcet methods and Hare versus Median Ratings methods like Majority Judgement and Bucklin

[Kristofer Munsterhjelm]

On 2024-04-10 15:36, Chris Benham wrote:

> But there is a very strong incentive for voters to just submit approval 
> ballots, and in a competitive election with
> informed voters the extra complexity versus simple Approval doesn't seem 
> to buy much.

I think there's a more general result:

Say we have a method that elects the candidate with the highest quality, 
and the quality of a candidate A only depends on each ballot's 
information about A (not on A's position relative to any other B). 
Suppose that the quality function f(A) is weakly monotone in the sense 
that if a voter raises (lowers) A, then f(A) can never decrease (increase).

Then with complete information, Approval strategy is optimal.

This covers both Range and MJ, and the most obvious way to make a 
general cardinal method pass IIA.

-km