<div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:trebuchet ms,sans-serif;font-size:small"><br></div></div><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jan 17, 2022 at 7:18 AM Colin Champion <colin.champion@routemaster.app> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Daniel – I’m a little unreassured by your figures, but it’s perfectly <br>
possible that the error is my own.<br></blockquote><div><br></div><div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small">Yeah. I would take that last table of numbers with a huge grain of salt. I'm ok with using the spatial model to get a rough measure of how easy it is to manipulate the election, but I haven't studied the subject enough to trust that I understand the rest. Speaking of not understanding, your page says:</div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small">"Voters and candidates are drawn from the same mixture of 3 two-dimensional gaussian components."</div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small">I don't understand what this means. In my program voters and candidates lie in an N-dimensional issue space (N=4 in my last email) and each coordinate is drawn from a standard normal distribution. So it's a multivariate gaussian where the covariance is the identity matrix. Is your program similar? I'm looking at your code (thank you for posting it) and I can't figure out where the voters and candidates are generated.</div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small"><br></div></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
It’s true that false cycles were my example (based on my preference <br>
for minimax) but similar phenomena occur elsewhere. Condorcet/Hare comes <br>
pretty close to minimax for percentage correct under burying (and <br>
outperforms ranked pairs) while looking much worse than both methods <br>
under Euclidean loss. My explanation was that IRV makes huge errors <br>
under sincere voting (see Table 2) and this property is bound to carry <br>
through.<br></blockquote><div><br></div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small">I just edited my program so it prints the Eucledian loss for sincere vs tactical voting, but so far I cannot reproduce your result. The Eucledian loss I get for Smith/IRV, Benham, Minimax, and IRV are not very different. I might need to make a lot of changes to reproduce your result (e.g. number of voters, number of dimensions, number of candidates, choice of tactics).</div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:"trebuchet ms",sans-serif;font-size:small">Cheers,</div></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><font face="trebuchet ms, sans-serif">Dr. Daniel Carrera</font></div><div dir="ltr"><font face="trebuchet ms, sans-serif">Postdoctoral Research Associate</font></div><div><font face="trebuchet ms, sans-serif">Iowa State University</font></div></div></div></div></div></div></div></div></div></div></div>