There is extraordinary growth in the relationship between perceptions of the prime minister and the electoral fortunes of the governments they lead. It’s a statistical analysis of our new primary dynamic.
We all know there’s a relationship between the vote a government receives in the polls and the satisfaction with the prime minister of the day. It’s hardly ground-breaking stuff — to show how it all plays out over the very long run (say, since 1986), we can simply chart the two-party preferred vote of the government of the day against the prime minister’s satisfaction rating, and do it again with the net satisfaction rating (where it’s satisfaction minus dissatisfaction). We’ll use Newspoll monthly averages …
I’ve added a simple linear regression line there to make the point — but it’s one worth covering quickly. The relationship here is statistically significant to all the usual levels and if we just look at that last chart, which compares the two-party preferred vote of the government against the prime minister’s net satisfaction rating, we find that changes in net satisfaction explain a little over half of the variation in the two-party preferred vote over the long term since 1986.
The stats just happen to play out in such a (fortuitous) way that if the net satisfaction of the prime minister was exactly zero — where there were as many people equally as satisfied with the PM as there were dissatisfied — we would expect the two-party preferred vote of the government to be exactly 50% to the nearest whole percentage. For every 10-point change in net satisfaction, we’d expect the two-party preferred vote to change by 1.3 points — towards the government with net satisfaction increases and away from the government with net satisfaction decreases.
So over the long term it’s been a solid relationship, but not an overwhelmingly dominant one — with the dynamic explaining 55% of the variation in the government’s two-party preferred.
Before we go any further, it’s worth noting that the relationship between the net satisfaction of the leader of the opposition and the two-party preferred vote of the opposition is completely non-existent over the long term …
A drunk bloke shooting paintballs on a chart comes to mind with that particular graphic. So the vote of the government is intrinsically linked to satisfaction levels of the Prime Minister in the general case, and the public’s satisfaction or otherwise with the opposition leader of the day is really neither here nor there. It’s all about the government/PM dynamic as far as this goes, and how the opposition strategies and tactics operate within that constraint. So if you tear down the PM, the government’s vote will go with it — hardly rocket science, but it explains a lot.
However, what you may not know is that while this relationship holds for all federal governments collectively since 1986 (as we’ve seen), it also holds for each individual government since 1986 — but with significant differences between them.