The maths of deciding who governs

James Riley
Thursday, 26 August 2010 13:07

IT Policy - Government Tech Policy

If nothing else politics is a game of numbers, and Victoria University mathematician Professor John Zeleznikow has cranked the numbers in the final three federal seats to be decided to work out who will form government.

The Australian Electoral Commission lists three undecideds: Brisbane, Hasluck and Corangamite. And in each of these electorates as in life, there is mathematics at play.

Zeleznikow says the numerical factors important to a calculation of likely outcomes are: the total vote cast, the existing margin between candidates, and the number of votes yet to be count.

He says the problem with the predictions of most analysts is that they are looking at the percentage difference between the two candidates, rather than the percentage of the remaining vote that a candidate needs to secure victory in the seat.

It is the number of votes yet to be counted that holds the key to what the likely result will be.

"If we examine each of the factors in turn, about 90 per cent of those on the roll are likely to cast a formal vote. Next we need to look at the margins between the parties in each seat," Zeleznikow said.

"Percentage-wise, Corangamite is closest at 0.34 per cent, but in this seat 85.95 per cent of votes are counted. The difference is 571 votes. To win, the Liberals need 1,800 of 3,000 remaining votes, about 60 per cent, which is unlikely," he said.

"In Brisbane the margin is 0.38 per cent, but only 73.40 per cent of votes have been counted. The difference is 490 votes. To win Labor needs 6,250 out of 12,000 votes: about 52.5 per cent. This is possible if the if the sitting member polls well in postal votes and other outstanding votes."

"Based on my calculations, I believe Corengamite will stay Labor and Hasluck will go to the Liberals."

So, according to the Victoria University mathematician and electoral analyst Professor Zeleznikow, the make up of the Parliament would then be Labor 72 and the Coalition 71 seats, with six others – three rural independents, one Green, one WA National sitting outside the Coalition tent, and an independent from Tasmania.

That leaves Brisbane. The seat will be "the closest fought, and could decide who forms Government," Zeleznikow said.