About Invalid Ballots in Burlington
2009 IRV mayoral election
Extracted (almost) verbatim from two posts by Juho Laatu
There were 8984 votes out of which
4 were listed as invalid in the official
results. These seem to be blank votes.
(At same time, voters
also could vote in City Council and other races
e.g. "School Commissioner" and "Inspector of Elections" and also
some yes/no referenda and hence it is
would not want to vote in the Mayor race.)
6 votes that contained ties. 4 of these
were exhausted at the first round. According
to Terry Bouricius 3 of these were found not
to be ties after all in the partial recount.
606 votes were exhausted before the final
round. Part of these are likely to be
intentional (voter didn't want to take a
position) but part of them were mistakes
of the voter. Either the voter didn't
understand how to cast an efficient vote
or the voter made false assumptions on
which candidates will make it to the
2458 votes ranked fewer than two of the
three leading candidates. If we assume
that any two of the three strongest
candidates could have made it to the last
round then these votes could have been
exhausted before the last round (due to
not listing any of the two last round
candidates). Again, some of these must
have been intentional and some voter
mistakes (due to not understanding how to
vote efficiently or due to miscalculating
The percentage of ballots that were not
filled properly was small.
The percentage of votes that failed or
could have failed to indicate all the
relevant preferences that the voter had
seems to be higher (part of the 606 and
2458 votes). This is not catastrophic
though. Maybe people will learn, or
maybe it is acceptable to have even
this kind of numbers in the long run.
(Some of the voters may also be bullet
voters by nature ("All or nothing",
"My candidate is the best and all
others are out of consideration", etc.)
Maybe they want to send this kind of
message in their vote (even though
they understand that they will cast
a weak vote).
It seems that ballots were not too
complex to fill properly, and most
voters also filled them well enough
to be counted also at the last round.
One remaining concern is that someone
said that the level of participation
(The number of votes in the Mayoral race, 8984,
was 43% of the number in the US presidential and VT governor
races held a few months previously.)
The complexity of the IRV method
may be in some degree responsible for this.
More data on the problematic ballots (=gaps)
(1=one mark, 0=no marks, 2=two marks,
five numbers for the five columns)
"Regular votes" with one candidate in
the leftmost columns:
10000: 1475 bullet votes
11000: 1891 votes that marked two candidates
11111: 2853 votes that used all the slots
In general the number of irregularly
marked ballots (ties and gaps) is quite
small (113). If we count the 1-slot
gaps as minor errors (that could happen
to anyone) then 46
bigger errors remain.
Some random observations:
In the one slot gap category there are
two 01111 votes that could be a result of
someone marking the candidates from
right (slot 5) to left (slot 1) in
reverse order. But since there are no
00111 and 00011 votes maybe these votes
are not that kind of mistakes either.
In the bigger than 2-slot gaps
category there were three 00001 voters.
These might be intended to be negative
votes. The other votes in this category
could be intended to contain both
positive and negative rankings/ratings.
In the one-slot gap category there are
38 11101 votes. Why so many? Did these
voters intentionally put the gap there
in the hope of making the last
candidate "lose more"?