
Shocking upset power of strategic voting - poshenloh
https://www.expii.com/solve/8/1
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mtgx
Interesting. I believe that with Ranked-Choice Voting Williams would be the
winner because only the top 2 with #1 ranking would be considered and then the
#2 ranking from the 15% group would be split between them, giving Williams the
win with 60% votes. With FPTP, Williams would also be the winner.

With approval voting, assuming they all pick only 2 (as picking 3 would mean
everyone gets 100%, and this post already assumes some "perfect voting"
anyway), Jones would also be the winner (just like in that post) with points
from 100% of the voters. Williams would be voted by 60% of the voters and
Smith would be voted by 40% of the voters.

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poshenloh
Correct! The fact that this breaks Ranked-Choice Voting is another reason why
this is an interesting example. If the each camp in the population were to sit
down and think what they'd prefer, the outcome would be in favor of Jones. So,
even if they were using Ranked-Choice voting, Camp 2 would strategically vote,
putting their favorite at the bottom, so that they end up better off overall.

Actually, Jones is what is known as the Condorcet winner in this election. :)

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mtgx
I'm trying to understand what's the difference between approval voting and
this, though. Does this have any advantage over approval voting?

Both systems seem to push the "overall most liked" candidate, but approval
voting has no artificial ranking other than "who has the most points", while
this one does. Although this one isn't as restrictive as RCV, which says "you
have to pick the top 2 before anything gets counted", which only makes it
closer to FPTP (even though it should be better than FPTP in some situations).

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poshenloh
Hi there!

This week problem features a very surprising voting paradox, which is directly
relevant to next week's primaries in the USA. It's a mathematical logic
puzzle, designed to stun with the enormous power of strategic voting. It's
also a public service announcement which is independently useful for informing
the public (just in time for the primaries) that it may not always be ideal to
vote for your favorite candidate. We designed it in a bite-sized (mobile) and
shareable format so that it could get the point across to as many people as
quickly as possible!

