4 ms·

I don't understand the focus on Condorcet- In a 3 party election run via IRV, the winner may represent the most conforming combination of positions of the peopl

I don't understand the focus on Condorcet- In a 3 party election run via IRV, the winner may represent the most conforming combination of positions of the people, but may not be the Condorcet winner. Therefore, Condorcet is not as aligned with best possible outcomes as IRV is. We've already learned that FPTP (which IS a Condorcet vote, quite directly) is suboptimal.

gamegoblin 4y ago
How is FPTP with > 2 candidates a Condorcet vote? A Condorcet method seeks to pick the candidate who would beat all other candidates in a 1-on-1 election. An N-way FPTP election is by definition not a 1-on-1 election.
- colinmhayes 4y ago
  FPTP never has > 2 candidates because everyone realizes that creates a spoiler.
  - gamegoblin 4y ago
    The 2000 US presidential election where Ralph Nader spoiled for Al Gore seems like a notable counterexample.
    - colinmhayes 4y ago
      And that election is why everyone now knows to not vote third party.
  - pmyteh 4y ago
    FPTP in non-US contexts very regularly has >2 candidates, despite the risk of a spoiler. England has a 2.5 party system where the Lib Dems compete in every seat and win some. Scotland and Wales have nationalist parties in addition to this (and the Scottish National Party is currently overwhelmingly dominant in seats won, as a result of one of FPTP's other failure modes). Northern Ireland has a different party system with sectional voting and ~5 effective parties. Canada has the NDP and (in Quebec) the Bloc. One of the classic results in political science is Duverger's Law, sometimes formulated as 'under first past the post the number of effective parties tends towards two', but 'tends towards' is doing an awful lot of work. One could unkindly suggest that, like a lot of political science results, it works better in the US than in the rest of the world. And I say that as a political scientist...

gamegoblin 4y ago

How is FPTP with > 2 candidates a Condorcet vote? A Condorcet method seeks to pick the candidate who would beat all other candidates in a 1-on-1 election. An N-way FPTP election is by definition not a 1-on-1 election.

colinmhayes 4y ago
FPTP never has > 2 candidates because everyone realizes that creates a spoiler.
- gamegoblin 4y ago
  The 2000 US presidential election where Ralph Nader spoiled for Al Gore seems like a notable counterexample.
  - colinmhayes 4y ago
    And that election is why everyone now knows to not vote third party.
- pmyteh 4y ago
  FPTP in non-US contexts very regularly has >2 candidates, despite the risk of a spoiler. England has a 2.5 party system where the Lib Dems compete in every seat and win some. Scotland and Wales have nationalist parties in addition to this (and the Scottish National Party is currently overwhelmingly dominant in seats won, as a result of one of FPTP's other failure modes). Northern Ireland has a different party system with sectional voting and ~5 effective parties. Canada has the NDP and (in Quebec) the Bloc. One of the classic results in political science is Duverger's Law, sometimes formulated as 'under first past the post the number of effective parties tends towards two', but 'tends towards' is doing an awful lot of work. One could unkindly suggest that, like a lot of political science results, it works better in the US than in the rest of the world. And I say that as a political scientist...