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Northern Ireland election

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The STV Clinic

  • Mark Devenport
  • 6 Mar 07, 12:32 PM

I have decided to elevate a comment I got on a previous entry to a full post as I know there's still a lot of confusion out there about the STV system. Maurice Martin asked "No one can explain to me how quota surpluses are distributed. Is it only the votes after the quota is reached that are transferred or do all the second preferences count? Our district has 16 candidates for 6 seats, how far down the list must I vote?"

Your last point is the easiest to answer - vote for as many or as few candidates as you like. It doesn't make any difference that there are only 6 MLAs per constituency. Because you cannot guarantee the order in which candidates might be elected or eliminated it's quite possible that a 7th, 8th or later preference could still have some bearing on the election.

The distribution of surpluses is more technical. The election officials do not simply take the stack of votes left over after a candidate is elected and count the second preference on those votes. If they did that it would discriminate against people whose second preferences would then be ignored.

Instead the officials count all the second preferences for victorious candidates and then divide them so they are portioned out in proportion to the surplus the winning candidate has accrued. They are then allocated at a reduced value. That's why you sometime get fractions of votes being transferred - they represent the outcome of the sum the officials do.

On the topic of STV here is, as they say on Blue Peter, one I prepared earlier. It's a film I recorded at a mock election in St Gemma's School in North Belfast around the European election in June 2004. With the help of the former returning officer, Joe Connolly, it was an attempt to explain STV.....

Comments   Post your comment

  • 1.
  • At 05:25 PM on 06 Mar 2007,
  • Gerard G wrote:

Mark what's your new blog gonna be called?

  • 2.
  • At 10:22 PM on 06 Mar 2007,
  • garethlee wrote:

hey mark, what's going to be the name of your new blog?

  • 3.
  • At 11:09 PM on 06 Mar 2007,
  • Alan wrote:

I read somewhere that the Belfast count wasn't be held in the City Hall this year. So where are they holding it?

(The local TV floor managers will be thankful for answers to their prayers - the background noise in the City Hall is awful, even when you're upstairs at a function.)

  • 4.
  • At 11:04 AM on 08 Mar 2007,
  • Niall wrote:

Mark,

I have a questions about the STV system. I understand how the surplus is distributed, but my question is how do you decide which votes to transfer? Surely depending on which sample you pick this may change the outcome, especially where the race is close.
An example might help.
Candidate 1 gets 10,000 votes, 1,000 above the quota. His/Her surplus is divided proportionately amongst each of the remaining candidates. Candidate 2 received 10% of the 2nd preferences of Candidate 1 so he/she will receive 100 votes. These 100 votes have to be drawn from a sample of 1,000 votes of Candidate 1 who have Candidate 2 as their second preference. Each of these 100 votes will have different 3rd, 4th and 5th preferences which may influence the vote later in the count. How are these 100 votes picked?
I hope this question makes sense!

MARK REPLIES: I had to consult with Prof Sidney Elliot and former returning officer Joe Connolly to answer this one....

They tell me that if transferred votes elect a candidate and the politician has a surplus left over, then only the package of votes which got the successful candidate over the line is counted.

If the politician is eliminated all his or her votes are looked at for preferences.

I think the theory is that in the fomer case the bulk of the successful candidates' votes have played a role in getting him or her elected, whereas if there is an elimination they won't have played such a part.

FORMER RETURNING OFFICER JOE CONNOLLY ADDS: Unlike eliminations, surpluses are treated in a different way. Surpluses arise because a candidate or candidates have been elected. In many cases they arise well into the count. These surplus votes, therefore, have responded well to the voters choices - these votes have done their job in getting candidates elected.
Eliminations are treated differently - if a candidate is eliminated half-way through the count - it's because not enough people voted for him/her - these votes if not dealt with would be wasted. Therefore, all the "parcels" of votes which the eliminated candidate received are re-examined to ensure they continue to play an essential part in the voting process. As a result, in this election only 14 - 15% of votes are actually wasted - playing no part in electing a candidate.

  • 5.
  • At 12:06 AM on 09 Mar 2007,
  • Niall wrote:

Thanks for all the replies, and I know its getting late for such a technical question but can you clarify the line below...

"They tell me that if transferred votes elect a candidate and the politician has a surplus left over, then only the package of votes which got the successful candidate over the line is counted."

The question remains how does the returning officer decide which specific "package of votes" to include in the surplus that you divvy up to the other candidates? Is it a random selection from all the votes that the successful candidate received?

  • 6.
  • At 03:55 AM on 09 Mar 2007,
  • stephen wilson wrote:

Mark, can someone explain why the parties practice 'vote management', I cant understand why it is necessary if the voters transfer within a party.
Supposin a party fields two candidates and gets exactly two quotas in FP's. If all of those voters put candidate A first and B second, then A's transfers would be transferred at half value, giving a full quota to B, precisely the same result as if the FP vote was evenly split. Why do parties want to equalise the FP vote, where are the votes lost?

MARK REPLIES: Votes leak because they are transferred at a reduced value, also some voters might just vote for the name they know and not bother passing on the transfer - that's why the parties try to divide up territory and get their supporters to follow instructions

  • 7.
  • At 03:09 PM on 09 Mar 2007,
  • Jonny Marr wrote:

I remember looking at the STV system in politics last year and was amazed at how complicated it was, fair credit to the people having to count up all those nasty ballots, I'm very impressed they've managed to get the results out as quick as they have.

  • 8.
  • At 10:08 PM on 09 Mar 2007,
  • Ronald wrote:

If I understand the above correctly then 2nd prefferences from eliminated candidates are then treated as full votes. If this is the case what happens to 2nd preference votes that are for candidates that have already reached the quota and been elected or for already eliminated candidates?

  • 9.
  • At 10:16 PM on 09 Mar 2007,
  • Ronald wrote:

Now that all the results are in - do you know if there will be tables published on all the STV count results and will they be on the web?

MARK REPLIES: I don't think we shall be publishing all the stages , but I think Nic Whyte's elections website has done that in the past

it's on

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