PM's spin turns off childless

One of Labor's best modern campaigners, Neville Wran, used to advise leaders to carefully select their campaign slogan, then just keep repeating it, no matter what.

He used to say that when you felt like you would throw up if you repeated it one more time, you would be just about getting through to the most apathetic of voters. Hence the repetition of the slogan working families by the Rudd team.

Australian Development Strategies' election modelling profile of the 2007 swing indicates that it seemed to have the desired result in some seats but did the exact opposite in others.

The profile initially looked pretty straightforward: most of the seats Kevin Rudd won was because median-income working families with young children, buying a home and driving a car to work from the outer suburbs, thought the Coalition didn't care enough about them.

There was also a resolution for change from the more activist religious groups that usually dominate the Christian school sector, and this delivered a disproportionate number of seats, especially in Queensland.

But there was movement back to the Coalition from an interesting group dominated by the rich, the well educated and the internationally qualified younger adults who tend to be clustered in the inner suburbs of capitals, and many of these voted Green first, Liberal second.

The reason for this counter-swing was a bit of a mystery to analysts at that time. We noticed an interesting trend in the results when we started to look more closely at the influence of age on the swing and the vote.

For the first time since we started profiling elections in 1966, we saw what seemed to be a divergence between parents and non-parents of the same age. Usually infants to four-year-old children have mothers in their 30s and this group is trying to re-enter the workforce, pay for a second car for another long commute, and juggle housing and childcare costs.

They are the classic swinging voters. Rudd offered them a much better deal for child care and they voted for it. Usually other 30-somethings without children would have followed suit. Get the first age group and you get the second group free.

However, this time the 30-something women with no children didn't follow the same pattern. Analysts decided to look beneath the surface of those who weren't working families with children, and enhanced their database to include women of various ages and their children.

For women with children, Rudd was the clear winner in terms of the swing to Labor. When the seats were ranked in terms of 30 to 34-year-old women with two children, analysts found they were looking at the outer urban-provincial seats won by the ALP, such as Lindsay, Flynn and Forde, or seats that should have been won by the ALP, including Greenway, Hughes and Dickson. The last three were retained narrowly on the personal votes of sitting Coalition MPs.

But when analysts looked at women without children, it was a different story.