[EM] (Fwd) STV and truncation

Steve Eppley seppley at alumni.caltech.edu
Wed Apr 3 20:25:02 PST 1996

```Kevin Hornbuckle:
>Steve Eppley:
>> Question: Does STV permit a voter to rank two candidates equally?  If
>> so, how do the votes transfer?  (The reason I ask is because unranked
>> candidates are essentially ranked *equally* last.  Do they share a
>> fraction of the ballot if it's "transferred" to the unranked?  I
>> assume they don't.)
>
>In fractional STV no votes are transferred to the unranked
>candidates. And yes, voters can rank candidates duplicatively.
>If I rank two candidates #1, each gets .50 of my vote. If one is
>eliminated, the vote value to the other increases to 1.

Doesn't this mean there's an inconsistency?  If leaving some
candidates unranked is shorthand for ranking them equally last,
shouldn't the truncated ballot be divided among all the unranked
when it's time to transfer it?

We've been using examples where we say {Nader,Clinton,Dole} is
equivalent to {Nader,Clinton} in a 3-candidate race.  But these
two ballots would transfer differently.  I guess this means that
what's shorthand in one system (single-winner) isn't shorthand in
another (multiwinner).

--Steve

```