[Election-Methods] Improved Approval Runoff

[Diego Renato]

All one-round voting systems that allows ballot truncation are vulnerable to
bullet voting, resulting the same results of plurality voting. For instance,
suppose that some voter has A as his/her first preference. S/he can vote
like this:

Approval: A: approved; B: rejected; C: rejected; D: rejected ...
Range (0 - 100 scale): A: 100; B: 0; C: 0; D: 0 ...
Preferential (IRV, Condorcet, etc): A>B=C=D=...

Additionally, there are several instances which only binary input voting
systems are reasonable. Complex systems are hard to adopt in low-educated
underdeveloped countries.

This system, called Improved Approval Runoff (IAR), has the goal to resist
bullet voting through simple ballots.

Description:

1) On the first round, the voter can vote for as many or as few candidates
as desired.
2) If some candidate has more than 50% of approvals, the most approved is
elected.
3) If not, that candidate runs a second round against other candidate - the
most approved after a new count which the votes for the first one are
reweighted to 1/2.
4) The winner is the candidate who receives a majority of votes on the
second round.

On computer simulations, the top-two approval runoff method selected more
times the Condorcet winner than any Condorcet method. I think that IAR is
slightly fairer than top-two approval runoff under real voters.

Any comments?

________________________________
Diego Santos
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