[EM] Fwd: Majority Judgement

[Jameson Quinn]

> (KM) I meant maximally strategic in the sense of "most favorably changes
the outcome in your direction". Voting Approval style should do that
because it works no matter what the honest median is.

JQ: Yes, but if, as you posited, the voter has perfect information on
others' votes, the honest winning median is known.

> (KM) The argument would go something like: say the probability of
changing the election in a way you prefer, if you vote Approval style, is
p_ms (for max strategy). Then if you're Homo Economicus, you know that if
you don't exaggerate maximally, the probability of the change after you
submit your somewhat-exaggerated ballot is p_ps and p_ps < p_ms. The margin
here may be really small, but if you're Homo Economicus, you take it no
matter how small.

JQ: yes, p_ps ≤ p_ms. But extra expression has some real value for
affecting future elections, and if (p_ms - p_ps) is not enough to offset
that value, then even Homo Economicus will vote the ps ballot. To put real
numbers on it: I think that once you have robust statistics and some
polling data, it is likely that you will be able to say that the
probability the median is within one rating of the highest rating is less
than 0.1%, so that you will have at least some safe expressive room at the
top.

Jameson
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