Leaders in Australia and New Zealand have floated the idea of a trans-Tasman bubble for some weeks now, as cases of coronavirus in both countries continue to drop, nearly in tandem. Why is it being raised now? The arrangement is principally motivated by economic necessity as both countries’ economies tank under tight lockdown restrictions, and recessions loom. Opening the borders would allow significant trade to resume (nearly 19,000 Australian businesses trade with New Zealand), as well as – at a minimum – tens of thousands of visitors each way. The morale boost for both populations is also not to be discounted. How could it work? If both countries agreed to an exclusive bubble arrangement, more flights would be put on by the national airline carriers, and the need for a two-week quarantine for all arrivals scrapped. The New Zealand prime minister, Jacinda Ardern, has hinted that New Zealand may not agree to open-slather travel with all states in Australia – as some have worse outbreaks than others, such as New South Wales, though she stressed this was a federal issue for Australia to resolve. How soon? There is a strong economic incentive to get the trans-Tasman borders open as soon as is safe, and the arrangement would also earn significant brownie points for both prime ministers. With New Zealand potentially moving to level 2 restrictions next week, and the New Zealand ski season opening just a month away, it is not impossible that borders could be open by early winter – as long as Australia is able to match New Zealand’s progress, which now stands at zero cases nationwide for two days. However, both prime ministers have refused to commit to a timetable, and Scott Morrison has ruled out anything as soon as “next week”, saying significant domestic travel would need to be under way – such as between Melbourne to Cairns – before New Zealand was welcomed into the fold. It appears that New Zealand is more eager for the arrangement than Australia, as tourism is the country’s biggest export earner. Who benefits? There are more than half a million New Zealanders living in Australia and 75,000 Australians living in New Zealand. For those with family stuck on either side of the ditch – elderly parents, baby grandchildren – this arrangement will allow families to be reunited. The tourism industry is the other clear winner – after the Chinese, New Zealanders holidaying in Australia are the country’s biggest visitor market, and the same stands for the Aussie tourism dollar in New Zealand. Australians make up 40% of the visitors to Queenstown ski fields (the most significant visitor market after Kiwis) and, according to NZSki, Australians are big spenders on hotels and dining out. The Queenstown mayor, Jim Boult, is an advocate of the trans-Tasman bubble, saying it could help his region survive: “We’d really love it to happen.” How has it been received? The proposal has huge support in New Zealand, especially from the business community. The foreign affairs minister and deputy prime minister, Winston Peters, has repeatedly championed the plan, saying he has been in regular discussions with his Australian counterparts about making it a reality. Peters said the relocation of the entire Warriors rugby team to NSW this week shows the plan “could work seriously well”, as the countries have “two of the most integrated economies in the world” and a history of cooperation and reciprocity. What could go wrong? Epidemiologists are widely supportive of the plan but say it will make contact tracing more difficult, and risk one or both countries re-entering stringent lockdown if cases emerge – or they can’t trust the other. Prof Michael Baker of Otago University is a fan – with caveats – and says the bubble could even be extended to Covid-19 success stories such as Taiwan or South Korea if and when they are declared virus-free. The inclusion of the Pacific Islands is also being considered. “You could conceive of a future where much of the eastern hemisphere is virus-free,” Baker told RNZ. “And that includes some of our major trading partners.”