[EM] Student government - what voting system to recommend?

[Bob Richard]

Tim Hull wrote:

> [...]
>
> I didn't even know there WAS a
> multi-winner IRV as distinct from STV.

Actually, there are (at least) one or two, depending on how far you
stretch the definition of single-winner IRV.

Some local elections in Australia are counted like STV without surplus
transfers (just successively eliminate defeated candidates).  They call
this "bottoms up".  I'm told that it results in a little bit of
proportionality but definitely not the same results as STV.

And, unfortunately, the U.S. state of North Carolina recently came up
with a multi-winner version of the contingent vote.  This is just my own
opinion, but I think it's actually worse than block voting because it
eliminates the usefulness of bullet voting.  They came up with it to
replace multi-winner top-two (my name for it), in which 2 * S candidates
advance to the second round, where S = number of seats.

> [...]
>
> As far as STV
> rules, I'm currently thinking standard fractional-transfer STV with
> voters allowed as many rankings as there are open seats allowed.  That
> would limit rankings, but would keep the ballot the same as it is
> currently [...]

I think this materially affects the representativeness of STV results
and should be avoided if humanly possible.  It reintroduces spoilers and
strategic voting -- at the slate/party level rather than the level of
individual candidates.  If I use all of my available rankings on the
slate I most prefer, I am no longer able to help my second-choice slate
defeat my last-choice one.  Eventually, slates learn to run only as many
candidates as they think will win (roughly the same problem as
cumulative voting).

I'm pretty sure this effect is larger in smaller constituencies with
fewer seats to fill.  (Can anyone help me clarify that point?)  See
below for more on constituency size.

> Just to clarify the situation, there is somewhere in the
> neighborhood of
> 47 representatives on the Assembly.  They are currently elected
> in two elections (half in each of them) - the President is elected in
> the Winter term one.  The representatives are divided into
> constituencies based on school/college.  The largest such division has
> 19 representatives, followed by 7 for the next largest, followed by a
> 6-seat one, a 3-seat one, and several 1 and 2 seat ones.

I'm not clear about the staggered terms.  Are the 19 seats all filled at
once, or are they filled 10 at one election and then 9 at the next?

I agree with you about staggered terms in general (the interfere with
STV), but 19 is a very large district magnitude for STV.  I doubt that
there's any agreement about the "best" upper bound on magnitude; I
personally think it's about 9 or 11 seats.  Is there any natural
subdivision of the 19-seat constituency (e.g. East Campus vs. West
Campus or Science vs. Humanities)?  Otherwise you may actually need the
staggered terms for that one school or college.

My two cents,
Bob Richard
Publications Director
Californians for Electoral Reform
http://www.cfer.org
P.O. Box 235
Kentfield, CA 94914-0235
(415) 256-9393