Talk:Arrow's impossibility theorem: Difference between revisions

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:: The Stanford article I linked, mentions some of the extensions. I think we should add sections to the page detailing these. It is important to say that these are not Arrow's theorem but extensions. They all have their own assumptions and limitations. As [[User:Kristomun|Kristomun]] says they come down to " majority plus something at least as powerful as ranked universal domain violates IIA". This means Score passes and so do several multimember score systems. It is really a restriction on majoritarian systems so maybe the title of the section should be "extensions to majoritarian systems". [[User:Psephomancy]] added a change to the page to clear up the wording and he added some references. --[[User:Dr. Edmonds|Dr. Edmonds]] ([[User talk:Dr. Edmonds|talk]]) 16:03, 20 March 2020 (UTC)

::: However, as I'd reiterate, an important point is that Range only passes if people don't calibrate their scales relatively. In the pizza election, they (presumably) have an absolute scale, but any normalization that reduces a two-candidate elction to a majority vote makes the procedure (plus implicit normalization) fail IIA. This point is probably stronger against Approval than Range: an absolute scale calibration implies that there can be voters in an Approval election who would approve every candidate or none of them, something which is very hard to imagine would happen in a real election. This is reminiscent of the Approval/Range "manual DSV" sleight of hand that I've talked about on EM. [[User:Kristomun|Kristomun]] ([[User talk:Kristomun|talk]]) 17:50, 20 March 2020 (UTC)