One of the persistent problems of a political class obsessed with polls, as Australia’s is, is a tendency to attribute every shift in voting intention in the polls to the events of the week or fortnight just passed.

Given the regular task of analysing polls, some of Australia’s best political journalists, who normally can effortlessly detect bullshit and agendas, can be found engaging in this sort of retrospective analysis, which risks attributing cause and effect where none exists.

The problem is reinforced by the fact that media outlets pay a lot of money for polling, and a poll revealing that not much has happened since the last one doesn’t make for particularly exciting coverage. There’s a natural tendency to talk up even small shifts as some significant change in the political landscape.

Yesterday Fairfax devoted considerable space to the narrative that last week’s budget had restored the Abbott government’s fortunes. But the Fairfax-Ipsos poll is an outlier — its 50-50 two-party preferred result is at odds with Newspoll (53-47) and today’s Essential Research poll (52-48), both of which suggest that the budget has had little impact on voter sentiment.

These narratives have a habit of becoming accepted political history even if they’re not true. And the narrative will be that Tony Abbott has staged a remarkable turnaround with the 2015 budget.

Perhaps he has — that remains to be seen. Or perhaps he has merely recovered from the dreadful polling he inflicted on his party with his bungles at the start of the year, back to where the Coalition spent most of 2014 — persistently four to six points behind Labor. But it’s not at all clear from the polls that the budget had much to do with it. Which for a political and media class that obsesses over the significance of the budget, is a rather inconvenient narrative.