------------ Forwarded Letter ------------- From: MIKE OSSIPOFF <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED], [EMAIL PROTECTED] Subject: RWE & Bucklin strategy. 3 candidates. Date: Tue, 08 Jun 1999 18:59:11 PDT Don-- Two points regarding your reply to Tannenwald: 1. RWE (Runoffs Without Eliminations) is incomparably better than IRV, with any number of candidates, including 3. RWE _doesn't_ give the same result as IRV in 3-candidate elections. Of course, with any 2 methods, there could be some particular examples where the 2 methods give the same result. In 3-candidate elections where the middle candidate's voters don't vote a 2nd choice, and where Middle gets eliminated first, and Middle is CW (Condorcet winner, the candidate who'd pairwise beat each of the others under sincere voting), RWE elects the CW, if at least one of the other candidates' supporters ranks the CW 2nd. An example: 40 25 35 A B C B B IRV starts by eliminating B, and, since the C voters' 2nd choice has been taken away, A wins. RWE declares B the lowest candidate, but his voters don't list a next choice to transfer to. The next lowest candidate is C. He transfers to B, who then has 60 votes, and is declared winner by RWE's stopping rule, since B now has votes greater than half the number of voters--B now has a majority. *** 2. I agree that RWE is considerably better than Bucklin, but I disagree with Tannenwald's statement that, if Bucklin is used, people should be somehow discouraged from doing strategic truncation. Truncation is the defensive strategy in Bucklin. One should avoid extending one's ranking farther than necessary. Avoid extending your ranking farther than what you estimate to be the best candidate that, with your help, can get a majority. Hoag & Hallett called truncation a failure of Bucklin; actually it's just the correct defensive strategy for that method. If people truncated too much, that would cause them to lose that lesser-evil compromise with which they could beat something worse. Maybe people over-truncated because they overestimated the winnability of their favorite. Maybe people unused to a method other than Plurality naturally tended to vote as in Plurality (and were inclined to vote sincerely in that method, as is often the case in municipal elections). The same truncation strategy is also the defensive strategy of RWE. Don't let CVD convince you that that's a bad thing. Though, in my opinion, there are better methods, the ones that have been called the VA methods, RWE improves hugely over IRV. It's worth examining the difference to show why that is: When I suggested RWE to Rob Richie, of CVD, as a very acceptable replacement for IRV, Richie, if I remember correctly, didn't like it because inclusion of a lower choice in one's ranking could defeat a higher choice. Sure it can, hence the defensive strategy I described. But does that make RWE worse than IRV? Note, please, that that lower choice in your ballot would never get a vote from you unless everyone whom you've ranked higher has transferred due to being lowest candidate. In IRV, everyone you've ranked above that lower choice would be eliminated. So the way IRV protects your upper choices from defeat by votes you give to your lower choices is by eliminating your upper choices when they transfer. IRV protects your upper choices by eliminating them. Thanks a lot, CVD. "Sire, the peasants have no shelter from the rain. They're attempting to shelter themselves with discarded newspapers and cardboard boxes. O won't you do something to end this deplorable situation?!" "Yes, slay the peasants". *** When I pointed out this obvious fallacy in CVD's objection to RWE, there was no reply. *** Feel free to forward this to Tannenwald &/or to EM, & any other list. *** Mike Ossipoff _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com
