Early deciding voters tend to base their decisions on a long-standing predisposition towards a particular party, as well as performance measures they know or can estimate long before the actual date of the next election.
Over the past three election campaigns an astonishingly high 73.8 per cent of National voters have reported reaching their voting decision before the start of the election campaign. These voters know the National-led Government, their policies, their ways of working and John Key's leadership.
National has a track record of stability and, incredibly for a third-term major party, has shown very few cracks in caucus unity.
If the past state of the economy has been positive - particularly if it has got better - early deciding voters use this to predict future trends. Economic indicators are still largely positive, aside from rampant house price inflation and lack of supply in Auckland. With a voter base that is predominantly comprised of homeowners whose asset values have risen, however, National voters will not be wanting or predicting the economy to tank between now and election day 2017.
Labour-leaning early deciders face a lot more unknowns, ranging from Labour's new vision and policies to whether Andrew Little has what it takes to be the next Prime Minister. It takes time to build credibility as a political party leader.
Jim Bolger and Helen Clark were leaders of the Opposition for 4.5 and six years respectively before becoming Prime Minister. John Key was leader of the National Party for just under two years before he became Prime Minister, but the opinion polls had already switched in National's favour when he took on his leadership role.
Also working against Labour's ability to secure the early vote is the May 31 Labour/Greens agreement to build a basis (my emphasis) "of a stable, credible and progressive alternative Government". It is a commitment to being more co-operative in the lead-up to the election, but it's not an offer of a coalition government and voters have to wait to see what it really means.
Labour might be thinking it has a bit of time up its sleeve. After all, only two-thirds of Labour's supporters reach their vote decision this far out from the campaign; the other third wait until the campaign to reach their decision. But Labour will have to work hard for the late deciding vote.
On average 41 per cent of voters who reach their decision during the campaign give their vote to a minor party. The next highest cohort (31.9 per cent) give their vote to the major party that ends up winning the highest proportion of the party vote. Labour hasn't won the majority of the late deciding vote since 2005.
It is also by no means guaranteed that joining forces with the Greens will see their combined vote rise. Late-deciding Labour and Greens voters tend to "eat each other's lunches". In other words, when Labour's late-deciding support rises, the Greens' support falls and vice versa. To be in a position to replace National, both Labour and the Greens need to attract late-deciding voters away from National and New Zealand First.
This will happen, but not until Labour is in position to switch places with National in the year before the election. Because this did not take place in 2016, history suggests we are at least two years away from Labour trading places with National in the opinion polls and four years before Andrew Little becomes Prime Minister.
- Professor Claire Robinson is a political commentator and Pro Vice-Chancellor of Massey University's College of Creative Arts.
