Outcomes from different electoral systems…

Using the same voter preferences:

     

 

Traditional ‘First past the post’ election: PEPPERONI wins

  • Only the 1st choice votes are considered (voters don’t indicate their 2nd or 3rd choices)
  • The candidate with the most votes wins


Pepperoni wins with 40% of the vote (but 60% of voters preferred another candidate)

Instant Runoff Voting: PEPPERONI wins

Round 1

  • 1st choice votes are counted
  • A candidate who gets over 50% wins
  • If no candidate gets over 50%, go on to Round 2

 

 

Round 2

  • Lowest vote getter is eliminated – Cheese is out
  • For those whose 1st choice votes were for Cheese, their 2nd choice votes are counted:
    • Pepperoni gets +16%
    • Veggie gets +12%

Pepperoni wins with >50% of the vote

Majority Voting: CHEESE wins

This system uses the same voter preferences and evaluates how each candidate would do in a series of head-to-head match-ups with the other candidates.

  • A candidate who beats all of the others wins

Head-to-Head: Pepperoni vs Cheese

Head-to-Head: Cheese vs Veggie

Head-to-Head: Pepperoni vs Veggie

Pepperoni beats Veggie (56 – 44), but since Cheese beat both of them, it’s not relevant.

In the head-to-head match-ups, Cheese beats both of its competitors: Cheese wins

 

IRV doesn’t always result in the candidate most preferred by a majority of the voters. Alternative versions of RCV provide that possibility.