In British Columbia some opponents of electoral reform have claimed that STV
always "wastes" a near quota of votes - those credited to the finally excluded
runner-up. I was asked if it would be possible, for any previous STV public
elections, to identify how many of the voters whose votes were "wasted" with the
runner-up might in fact be "represented" by one of the winners because they had
marked a higher preference for one of the winners but their vote could not be
transferred because that winner had already been elected.

That calculation MIGHT be possible, though it would be quite difficult as one
would need to track every individual ballot paper through the counting stages.
Also, if those "wasted" voters were to be "reclaimed", it would be appropriate
to reclaim also those voters whose ballot papers had been set aside as
"exhausted" at an earlier stage but who had also marked a higher preference for
an already elected winner. Again, it would be difficult to indentify such
ballot papers and so count such voters.

I discussed this question of how best to measure "represented voters" with Lewis
Baston, the Research Director of the Electoral Reform Society, and we agreed
that the most appropriate measure of "satisfactory representation" or
"represented voters" would be the percentage of voters who had marked an
appropriate preference for any one of the winners in the respective electoral
district. In a 3-member electoral district, the "cut-off" would be the 3rd
preference and in a 4-member electoral district the cut-off would be the 4th
preference.

Preferences beyond these may have contributed to the election of some of the
winners, but there could be debate about how well "represented" a voter was who
had given her 6th preference to one of the 3 winners when there were 10
candidates standing. So to avoid all such indeterminable discussion, Lewis and
I agreed the cut-off should be at the preference that corresponded directly with
the respective number of winners.

There can be no dispute that if you gave your first preference to one of the
four winners in a 4-member electoral district, you are "represented". We
thought it is equally justified to describe you as "represented" if you gave
your fourth preference to one of the four winners in a 4-member electoral
district. Some voters may well have given their first and second preferences
(or second and fourth, etc, etc) for two of the four winners (or more), so in
determining the "represented voters" it is essential to avoid double, triple and
quadruple counting.

The full ballot data from the Glasgow City Council elections in May 2007 are
publicly available (on the City Council's website) and so I have used them.
There are 21 wards in Glasgow ("ward" = "electoral district" for local
government elections in the UK), but here I present the results only for the 16
four-member wards. There were only five 3-member wards. I plan to prepare a
full analysis for publication in 'Voting matters'.

On the basis that we can define a "represented voter" as stated above, I have
tabulated:
1. voters who gave their 1st preference to a winning candidate.
2. excluding those already represented by their 1st choice candidate, voters
who gave their 2nd preference to a winning candidate.
3. excluding those already represented by their 1st or 2nd choice candidate,
voters who gave their 3rd preference to a winning candidate.
4. excluding those already represented by their 1st or 2nd or 3rd choice
candidate, voters who gave their 4th preference to a winning candidate.

There was an average of 10.1 candidates (range 8 - 13) in these 16 wards The
average percentages of "represented voters" in the 16 four-member wards were:
_Voters represented by winner
__1st___1-2nd___1-3rd___1-4th____NOT represented
__73%____86%_____89%_____90%______10%

I have prepared a series of charts that show the results for each of the 16
wards. These can be opened or downloaded from either of two sites:


http://www.jamesgilmour.f2s.com/Glasgow07/Voters-Represented-by-1st-Choice-Winne\
rs.pdf


http://www.jamesgilmour.f2s.com/Glasgow07/Voters-Represented-by-1st-or-2nd-Choic\
e-Winners.pdf


http://www.jamesgilmour.f2s.com/Glasgow07/Voters-Represented-by-1st-or-2nd-or-3r\
d-Choice-Winners.pdf


http://www.jamesgilmour.f2s.com/Glasgow07/Voters-Represented-by-1st-or-2nd-or-3r\
d-or-4th-Choice-Winners.pdf


http://www.jamesgilmour.f2s.com/Glasgow07/Voters-Represented-by-1st-to-4th-Choic\
e-Winners.pdf

or from


http://www.jamesgilmour.org.uk/Glasgow07/Voters-Represented-by-1st-Choice-Winner\
s.pdf


http://www.jamesgilmour.org.uk/Glasgow07/Voters-Represented-by-1st-or-2nd-Choice\
-Winners.pdf


http://www.jamesgilmour.org.uk/Glasgow07/Voters-Represented-by-1st-or-2nd-or-3rd\
-Choice-Winners.pdf


http://www.jamesgilmour.org.uk/Glasgow07/Voters-Represented-by-1st-or-2nd-or-3rd\
-or-4th-Choice-Winners.pdf


http://www.jamesgilmour.org.uk/Glasgow07/Voters-Represented-by-1st-to-4th-Choice\
-Winners.pdf


The message from these STV-PR elections seems clear.

James Gilmour