A funny thing happened to provisional votes at the November 24 election. It probably cost the ALP several seats. Or it prevented them from taking several seats they shouldn’t have. Or perhaps 70,000 – 100,000 people who couldn’t be bothered keeping their enrolment details up to date simply got what they deserved.

It’s in the eye of the beholder.

What is a provisional vote? Broadly speaking, this is when an elector rocks up to a polling station on election-day, gives their name to the official but finds they aren’t on the roll.

So they get a ballot paper, fill it in, and also write their name and address and electorate on an envelope, into which the ballot paper goes. In the next week or so the AEC checks the voter’s bona fides and if the AEC agrees they should indeed have been on the roll, their ballot paper is counted.

At the 2004 election, about twelve and a half million people voted across the country. Some 180,878 people went through the provisional vote process described above, and of those, 90,366 were rejected, and 90,512 accepted.

So almost exactly 50% made it into the count in 2004.

At last month’s election, nearly 13 million people voted in total, and there were (none of the 2007 figures is final) 168,767 provisional votes received by the AEC.

But only 24,212 were counted; the rest were rejected. That is, the acceptance rate of provisional votes fell from 50 percent in 2004 to 14 percent in 2007. Why?

The Howard government made several changes to the electoral law in the last few years, but one of them largely accounts for this huge drop.

Under the old rules, if a person moved from one house to another in the same electorate, and the AEC found out they had left Dwelling A, and so took them off the roll there, but didn’t put them on at Dwelling B because the voter hadn’t filled out a change of address form, they were still entitled to have their vote counted. (If they had moved to another electorate and had dropped off the roll they couldn’t vote.)

But that rule is no more, and such people were discarded in the preliminary scrutiny after last month’s election.

The remaining 14 percent – those who were accepted – were accidentally taken off by the AEC, could show they hadn’t moved address, or were mistakenly thought to have died, perhaps.

Does all of this matter? From the point of view of the disenfranchised elector it does, although some argue that if you can’t be bothered keeping your AEC details up to date you have no-one to blame but yourself.

There is also the fact that provisional voters are disproportionately left of centre. For example, the total national vote at the 2004 election split, after preferences, about 53 to 47 in the Coalition’s favour. But provisional votes split about 53 to 47 to the ALP.

Last month, the nation voted about 53 to 47 in Labor’s favour. Can we assume the “missing” provisional votes would have swung by the same amount, and so gone 59 to 41 in Labor’s favour? If we do assume that, then they would have added about .1 percent to Labor’s national vote, and given them a few more seats.

Or maybe they wouldn’t have swung by that much, and probably at least some of the “missing” provisionals should not have been counted anyway. But even a conservative treatment of them delivers Labor the ultra-marginal McEwen and Bowman.

Electoral law is not black and white. The tension is between integrity of the roll and people’s right to vote. Throw in partisan considerations – from both sides – and it’s a heady mix.

The Coalition government has rammed through some long-held hobby horses since taking control of the Senate in 2005. The new Labor government will have its own, although passage through the Senate may be tricky.

Any electoral system must guard against fraud. But the fact is – and all political parties know it – that the legitimate electors who are likely to lose their vote under tighter restrictions – renters, young folks, people who move around a lot, those without a drivers license – tend to vote left of centre in greater numbers than the rest of us.

This informs the parties’ approach to electoral law.

The Australian Electoral Commission runs a first class operation on election-day. Beneath the calm, efficient exterior at the polling booth is a massive logistical exercise that remains the envy of much of the planet.

But on enrolment we have fallen behind world’s best practice. In many countries address changes are automatic – you don’t have to tell the officials, they change your details for you – and in others enrolment and detail changes are possible up until polling day.

It’s time for Australian enrolment procedures to move into the 21st century. Then issues such as provisional voting would hardly arise.