[EM] STV and STV-PR

[James Gilmour]

> Stephane Rouillon> Sent: 16 October 2006 21:18
> 
> Sorry for asking a question most people already know, but
> Is there any difference between STV and STV-PR systems or are 
> they simply two names for the same model? If not what is the 
> difference?

In a word, no.  But as we all know, STV can be used in single-winner
elections, when it will NOT give PR of anything, even when there are
many single-winner elections, one in each single-member district.
Fairshare (here in Scotland) adopted the term "STV-PR" during its
campaign for STV-PR for local government elections because some
opponents of PR jumped on the "STV" bandwagon to promote what we call
the "Alternative Vote" and US reformers usually call "IRV", i.e. STV
single-winner elections in each separate single-member district.  (We
have 32 local councils with 18 to 80 members.)  We were concerned that
public and media references to "STV" could be taken to mean what we did
NOT want.

Similarly, I avoid the term "PR" when referring to any specific voting
system, because again, it suits some folk to blur the very clear
distinction that exists between all forms of "Party PR" on the one hand
and "STV-PR" on the other.   It is, however, useful to use the generic
term "proportional representation" (PR) when you are making a contrast
with a non-PR voting system like plurality or IRV.

James