<story><title>Instant runoff voting is the system we need</title><url>http://chuckgreenman.posthaven.com/instant-runoff-voting-is-the-system-we-need</url></story><parent_chain><item><author>xvedejas</author><text>I&amp;#x27;m continually upset and confused by Instant runoff voting&amp;#x27;s popularity. IRV is, by my reckoning, a much inferior (and more complicated) system than other systems, like range voting or ranked pairs. And it has some bizarre properties that make me wonder if it is even worse than the traditional first-past-the-post.&lt;p&gt;One property of IRV that makes it so questionable is its non-monotonicity. This means that you can help a candidate by ranking them lower, and hurt a candidate by ranking them higher. It is extremely easy to visualize how ill-behaved IRV is in the charts on this website:&lt;p&gt;&lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;zesty.ca&amp;#x2F;voting&amp;#x2F;sim&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;zesty.ca&amp;#x2F;voting&amp;#x2F;sim&amp;#x2F;&lt;/a&gt;&lt;p&gt;Meanwhile, ranked pairs (a &amp;quot;condorcet&amp;quot; method) has the property that, if candidate A is more popular than all other candidates pairwise, then candidate A will always win. This is _not_ true in IRV.&lt;p&gt;If you&amp;#x27;re interested in falling down the rabbit hole of electoral systems, I recommend looking at this chart that compares their properties:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Comparison_of_electoral_systems#Comparisons&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Comparison_of_electoral_system...&lt;/a&gt;</text></item></parent_chain><comment><author>cwmma</author><text>Runoffs are something people understand, IRV is conceptually similar and makes intuitive sense to people, it&amp;#x27;s very easy to explain to people, &amp;#x27;if nobody gets a majority, eliminate last place and redistribute their votes, repeat&amp;#x27;.&lt;p&gt;Compare that to to some of the other systems which often have complex mathematical descriptions which are hard for people to wrap their heads around.&lt;p&gt;Another thing is how big a deal is &amp;#x27;non-monotonicity&amp;#x27; is it actually going to be something that will affect elections all the time, or is it something that&amp;#x27;s more minor than say turnout which honestly has no solution and on one side you have USA where turnout is low so the game is all about making sure your base turns out, or on the other side you have Australia where voting is mandatory so making sure people who don&amp;#x27;t care, don&amp;#x27;t vote at random is a big part of the game.</text></comment>
<story><title>Instant runoff voting is the system we need</title><url>http://chuckgreenman.posthaven.com/instant-runoff-voting-is-the-system-we-need</url></story><parent_chain><item><author>xvedejas</author><text>I&amp;#x27;m continually upset and confused by Instant runoff voting&amp;#x27;s popularity. IRV is, by my reckoning, a much inferior (and more complicated) system than other systems, like range voting or ranked pairs. And it has some bizarre properties that make me wonder if it is even worse than the traditional first-past-the-post.&lt;p&gt;One property of IRV that makes it so questionable is its non-monotonicity. This means that you can help a candidate by ranking them lower, and hurt a candidate by ranking them higher. It is extremely easy to visualize how ill-behaved IRV is in the charts on this website:&lt;p&gt;&lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;zesty.ca&amp;#x2F;voting&amp;#x2F;sim&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;zesty.ca&amp;#x2F;voting&amp;#x2F;sim&amp;#x2F;&lt;/a&gt;&lt;p&gt;Meanwhile, ranked pairs (a &amp;quot;condorcet&amp;quot; method) has the property that, if candidate A is more popular than all other candidates pairwise, then candidate A will always win. This is _not_ true in IRV.&lt;p&gt;If you&amp;#x27;re interested in falling down the rabbit hole of electoral systems, I recommend looking at this chart that compares their properties:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Comparison_of_electoral_systems#Comparisons&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Comparison_of_electoral_system...&lt;/a&gt;</text></item></parent_chain><comment><author>clarkevans</author><text>To me it also seems IRV is complicated. That said, doesn&amp;#x27;t the non-monotonicity property of IRV support outcomes where a compromise candidate might win when they otherwise would lose? That doesn&amp;#x27;t seem to be a bad thing.  If people vote strategically to make a centrist their 1st vote to avoid what they consider an extreme, that seems like the essence of political compromise and an improvement over 1st past post.&lt;p&gt;Perhaps the most important important property of a voting system is that it is easy to grok, so that people trust it. In particular, aggregates at the local level should combine simply with other districts to tally overall winners.You can tally IRV incrementally, it&amp;#x27;s just that ranking permutations are the units of aggregation. That&amp;#x27;s non-trivial. For this reason, I prefer approval voting.</text></comment>