4 ms·

I'm really not sure people realize how chaotic and unpredictable ranked choice voting can be, and how easily it can be gamed. For example, there are scenarios

I'm really not sure people realize how chaotic and unpredictable ranked choice voting can be, and how easily it can be gamed. For example, there are scenarios where it's better to put your favorite candidate in #3. You pick #1 to help an undervoted candidate and therefore, causing one candidate to drop off. Same for #2. By the time the choice comes to #3, your minority candidate has suddenly managed to eliminate stronger opposition just by playing numbers. We've seen this scenario happen repeatedly in all countries and counties that have tried this approach. There's a reason ranked choice voting is hardly ever used anywhere: it's really not such a good idea.

orthecreedence 10y ago
As opposed to FPTP, which is almost always demonstrably worse and forces gaming the system by its nature. You can very seldom vote for who you actually want. So maybe STV/IRV are bad, but they can't be worse than what we have now...unless you favor predictability over representation.
mcbits 10y ago
I don't follow your scenario. Can you give a real example? If you put your favorite candidate in the #3 spot, it would make them more likely to be the one that drops in round 1 or 2, no?
- hota_mazi 10y ago
  Here is a real world situation that happened in 2010 in Oakland: http://www.nytimes.com/2010/11/12/us/politics/12bcvoting.html http://www.nytimes.com/2010/11/12/us/politics/12bcvoting.htm...
  - lambertsimnel 10y ago
    Surely to vote based on that is to bet on other like-minded voters not doing the same, while tactical voting under FPTP/plurality voting involves betting that like-minded people will do the same.
  - mcbits 10y ago
    That looks like an example of RCV working as intended. The candidate with a lot of support didn't win because a lot of people also strongly opposed him. I don't see how he would have won if his supporters made him their #2 or #3 choice instead of #1.
- Chathamization 10y ago
  Here's a couple of examples of how RCV might have played out if it was in effect for the 2016 election: Scenario 1: Clinton, Sanders, and Trump are all running. Clinton and Sanders supporters assume Trump will lose. Clinton and Sanders spend most of their time attacking each other. Since supporters of Clinton and Sanders don't bother making a second pick (since they don't want to support their opponent, and assume Trump is going to lose anyway). Clinton and Sanders each get 32%, and Trump wins with 36%. Scenario 2: Imagine a scenario where there are lots of candidates running. Something like the GOP and Democratic primaries this year, but everyone running in the general. Like this year, there are 5 candidates running on the left and 17 running on the right. Most voters aren't going to bother ranking all 22 candidates, and only rank 1-3. This causes the left to win simply because they have fewer candidates. The thing is, many comments seem to assume that people would rationally rank all of their choices. But people don't really act like that. Some will, some will just pick their favorite, some will rank only the people they're familiar with, etc. The current system (with the primary acting as a run-off vote) allows people to reflect on new information (these are the top two candidates and this is what they believe) before making a choice. RCV seems to just kind of hope that people think about these things ahead of time (and people usually don't).
  - mcbits 10y ago
    There are many scenarios (e.g. Cruz or Rubio might have stayed in), but I'm curious about one where it would be rational to rank your preferred candidate as #2 or #3 or beyond to help them win.
  - TimJRobinson 10y ago
    Both of those outcomes are because the hypothetical voters made stupid decisions, not because the system is flawed. If they choose to not take advantage of writing out all their preferences it's their own fault when they don't get what they want. I don't see how FPTP would be better in either example, you'd just get the same or worse outcome.
caf 10y ago
This scenario does not actually play out in practice, because in order vote tactically in this way you need to be able to predict in which order the candidates will finish. If you're wrong - say, by too many people voting in the same way as you - you can could easily find your the candidate you ranked #2 defeating the candidate you ranked #3 (that you really preferred) with the help of your vote. So yes, there are times when after the election you can see that you could have voted tactically for someone other than your most preferred candidate in order to assist them, but you can't easily or perfectly predict this beforehand.

orthecreedence 10y ago

As opposed to FPTP, which is almost always demonstrably worse and forces gaming the system by its nature. You can very seldom vote for who you actually want. So maybe STV/IRV are bad, but they can't be worse than what we have now...unless you favor predictability over representation.

mcbits 10y ago

I don't follow your scenario. Can you give a real example? If you put your favorite candidate in the #3 spot, it would make them more likely to be the one that drops in round 1 or 2, no?

hota_mazi 10y ago
Here is a real world situation that happened in 2010 in Oakland: http://www.nytimes.com/2010/11/12/us/politics/12bcvoting.html http://www.nytimes.com/2010/11/12/us/politics/12bcvoting.htm...
- lambertsimnel 10y ago
  Surely to vote based on that is to bet on other like-minded voters not doing the same, while tactical voting under FPTP/plurality voting involves betting that like-minded people will do the same.
- mcbits 10y ago
  That looks like an example of RCV working as intended. The candidate with a lot of support didn't win because a lot of people also strongly opposed him. I don't see how he would have won if his supporters made him their #2 or #3 choice instead of #1.
Chathamization 10y ago
Here's a couple of examples of how RCV might have played out if it was in effect for the 2016 election: Scenario 1: Clinton, Sanders, and Trump are all running. Clinton and Sanders supporters assume Trump will lose. Clinton and Sanders spend most of their time attacking each other. Since supporters of Clinton and Sanders don't bother making a second pick (since they don't want to support their opponent, and assume Trump is going to lose anyway). Clinton and Sanders each get 32%, and Trump wins with 36%. Scenario 2: Imagine a scenario where there are lots of candidates running. Something like the GOP and Democratic primaries this year, but everyone running in the general. Like this year, there are 5 candidates running on the left and 17 running on the right. Most voters aren't going to bother ranking all 22 candidates, and only rank 1-3. This causes the left to win simply because they have fewer candidates. The thing is, many comments seem to assume that people would rationally rank all of their choices. But people don't really act like that. Some will, some will just pick their favorite, some will rank only the people they're familiar with, etc. The current system (with the primary acting as a run-off vote) allows people to reflect on new information (these are the top two candidates and this is what they believe) before making a choice. RCV seems to just kind of hope that people think about these things ahead of time (and people usually don't).
- mcbits 10y ago
  There are many scenarios (e.g. Cruz or Rubio might have stayed in), but I'm curious about one where it would be rational to rank your preferred candidate as #2 or #3 or beyond to help them win.
- TimJRobinson 10y ago
  Both of those outcomes are because the hypothetical voters made stupid decisions, not because the system is flawed. If they choose to not take advantage of writing out all their preferences it's their own fault when they don't get what they want. I don't see how FPTP would be better in either example, you'd just get the same or worse outcome.

caf 10y ago

This scenario does not actually play out in practice, because in order vote tactically in this way you need to be able to predict in which order the candidates will finish. If you're wrong - say, by too many people voting in the same way as you - you can could easily find your the candidate you ranked #2 defeating the candidate you ranked #3 (that you really preferred) with the help of your vote. So yes, there are times when after the election you can see that you could have voted tactically for someone other than your most preferred candidate in order to assist them, but you can't easily or perfectly predict this beforehand.