Who doesn't love a good "what if" story?
What if Adolf Hitler had been accepted into the Vienna art school in 1907?
What if Lee Harvey Oswald had missed?
What if Jimmy Neesham hadn't run himself out last week?
History is littered with pivotal moments in time. Some quantum physicists even argue that every possible path of history exists in an infinite multi-verse of alternate realities.
Science-fiction writers haven't waited for proof of that. Multi-verse theory is a staple of pop culture – from kids' cartoons to heavyweight novels re-imagining the political landscape of the world.
On this theme, my imagination was sparked by Stats NZ's recent revision of immigration data.
The belief that immigration was at record levels in mid-2017 was central to the election campaign that year.
It certainly added momentum to the New Zealand First campaign, with Winston Peters targeting it as a hot button.
In 2016 we'd seen fears about immigration drive populist political upsets in the US and UK. There was a rich vein of public discontent to be mined.
Labour also initially campaigned on slashing immigration numbers – although it pulled back on hard numbers when Jacinda Ardern took the leadership.
Record immigration numbers were being blamed for the housing shortage and for crowded roads, schools and other infrastructure.
At the more nuanced end of the political debate, the numbers were also used to undermine National's economic growth story.
The "rock star economy" didn't look quite so flash when you looked at GDP growth on a per capita basis as opposed to just topline GDP.
But it turns out immigration was not at record levels of 72,500 in mid-2017. Immigration had peaked a year earlier at 64,000
What might a full year of headlines about falling immigration have done to undercut the issue's power in the election?
Previously we'd been basing our immigration numbers on the intentions that long-term arrivals wrote down on those annoying little cards we get at the airport.
That failed to account for the people that were changing their minds and leaving earlier or staying longer.
Now we have the technology in place to measure those additional movements and the net result is there are less people sticking around than we thought.
We don't even have to fill out the cards anymore.
The Stats NZ update – released on the Friday before Auckland Anniversary weekend – looked pretty arcane and didn't get much coverage.
Then Westpac economist Satish Ranchhod wrote a report noting that these new numbers had significant impact on the economy.
New Zealand's immigration rate is still high by historic (and international) standards but the more accurate numbers show that, in the year to November, 20,000 fewer people settled here.
Would more accurate data have changed the election result?
It may have changed sentiment but would have to have shaved more than 2.2 per cent off the New Zealand First result.
Peters finished with 7.2 per cent of the vote and nine seats. But the way the rest of the votes fell he would have been kingmaker with anything above the 5 per cent threshold.
Perhaps Labour's vote might also have been undermined, but that seems less likely given the wave of Jacindamania which overshadowed its other policies.
Could it have been enough at the margins to see the Māori Party win the tight race for the Waiariki seat? We'll never know.
Former finance minister and National Party campaign manager Steven Joyce doesn't believe it would have made a difference in the end.
He revealed on Twitter that it was his concern about the flaws in the immigration numbers, way back in 2016, that prompted Stats NZ's policy review.
To his credit he didn't fast-track the process prior to the election.
Perhaps he's also being a bit gracious in defeat, no wants to hear a retired politician's sour grapes.
An alternate reality where Bill English leads a government with similar policies of fiscal prudence but tackles the housing crisis in a less centralised manner obviously wouldn't make as good a movie as one about a world where the Roman Empire never fell.
But that's New Zealand for you. It's a reminder of how mild the political shifts and swings have become in the past couple of decades.
Meanwhile, in this little corner of the multi-verse, the implications of the revised statistics are still to play out.
New immigrants have to live somewhere and if there are 20,000 fewer arriving every year then that implies less houses are needed to meet demand.
The Auckland housing market is already seeing prices fall just as building consents are hitting record levels (touch wood on this data).
How might the lower (and still decreasing) immigration rate play into this?
It should ease pressure on the Government to ramp up its KiwiBuild programme.
Given the fire they are under on that right now it's unlikely they'll use it as an excuse.
But the lower population track and falling house prices do offer them a way to duck out of the building dilemma before the next election.
Unfortunately, given the fine and fickle balance of public opinion, lower immigration may also see them struggle to manage fears about a housing slump and slowing economy.