This feels like such a weird proposal to me. We're separate countries... Internationally we get conflated a lot, I guess because we're both in the same corner of the world and we don't come up much in the news, but on the ground AU and NZ are quite different countries.
I don't think there's any problem with the current state of affairs. Trying to merge into being a different country would be so much administrative overhead when we have bigger problems within the country we have to solve.
I guess it might also negatively impact Maori people since there's a greater chance of them losing their special affordances and being socially "merged in" with the rest of AU's indigenous population?
If the reason for this proposal is for trade deals and such, we already have those. NZers and AUians can travel back and forth without a visa, attend university without paying international fees, work abroad, etc.
I don't really get it. If there's a good argument for it, I could have easily have my mind changed, but right now it just sounds bizarre.
NZ population is roughly the same as Melbourne. For us it would be a benefit to have access to the vast resources and wealth Australia has at their disposal. Honestly I don't know what they would get out of the deal. We would be an albatross across their neck.