The Government's made the right call pausing the transtasman bubble this week.
If the Australian experience during the past month has taught us anything, it's that Delta changes the risk calculation.
This is the first Covid variant that has had NSW beat. Up to now, that state has been able to get on top of outbreaks without going into widespread, drawn-out lockdowns. They've managed to tidy up Covid outbreaks often using contact tracing.
But Delta has got the better of NSW. Even after four weeks of restrictions, case numbers keep rising.
Delta is simply more infectious.
Most likely, even one case of Delta in NZ would be enough to put the affected city and region into a level 3 lockdown at the least.
Therefore, this becomes a simple economic calculation. Keep the bubble open and risk an expensive level 3 lockdown or close it and lose the business flowing over the Tasman for eight weeks.
The cost of level 3 is about $250 million a week in Auckland alone. A lockdown across the country would cost considerably more.
The loss of tourism from closing the border is estimated at $14m a week according to Covid-19 Response Minister Chris Hipkins. Given that travel from NSW and Victoria are shut down anyway because of their outbreaks, the bubble is of much reduced value right now.
That makes the maths reasonably simple.
While closing the border to unaffected states like Western Australia and Tasmania may seem overkill, the truth is land borders are proving untrustworthy. Already 111 people (we're aware of) have been busted trying to come into NZ, lying about where their journey started. Presumably they've snuck from a hot spot into another state, flown across the Tasman and told a porky. They're now doing two weeks in MIQ.
An eight-week pause may also seem overkill. And let's hope it proves to be. But the way the NSW Covid is spreading, it is entirely possible that state is still grappling with this outbreak in late September. The fact that there are daily several dozen infectious cases roaming around the community is not a good sign. That number hit 48 on Friday.
Of course, we are also partly to blame for needing to close the border. Our border controls are still so weak that officials still aren't asking all arrivals for proof of predeparture testing. That was supposed to be implemented in May. At last count 100 people (we're aware of) arrived without getting the Covid all-clear ahead of jumping on the plane.
What's more, we simply don't have the vaccination cover most other developed countries do. Authorities have only double-jabbed 13 per cent of the population, they've only just started seriously inviting our vulnerable Kiwis for their vaccines and the Government is still trying to figure out the fairly simple premise of how to get GPs and pharmacies delivering jabs.
We are very close to being sitting ducks for Delta. We're now the only Covid elimination country that hasn't had Delta run through it. Australia, Taiwan, Singapore, Vietnam, Laos. You can count every one of them and more off the list. We are the last one standing and we are pushing our luck in a big way, being as chill as we are about ramping up the vaccine rollout.
So, lest the luck run out, good move closing the border for now.