Instructions:
Move a vote from p>r>q to q>r>p by clicking the “Change Vote” button below, and let the red point come to rest.
Click the button again to change it back.
Now add a vote to q>r>p by clicking on its point. What happens to the outcome with this additional vote? How is the winner related to the ranking of the additional vote?
▷ Explanation:
Suppose all ties are to be broken via alphabetical order. Then the voter here with sincere preferences p>r>q might wish to flip his ranking upside down, casting q>r>p. Pre-flip, the winner is r. Post-flip, a three-way tie is broken in favor of p, the manipulating voter’s top choice. This situation represents a failure of irresolute half-way monotonicity, hence of irresolute one-way monotonicity.
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