I keep reading comments on websites and hearing general chatter that question why we must catch Australia. Like, what's the big deal? Or, who cares?
Here's the answer in simple terms.
It's very easy to travel these days. So much so that tens of thousands find it easy to leap across the ditch for better weather or better life opportunities. If we keep losing people to the extent we are, our tax base reduces. It is reducing further as our population ages. In fact, not only does it reduce, as our population ages, and it is aging fast, greater stresses will be put on superannuation and health. That will require more tax revenue. If more people leave Godzone, fewer people and businesses will end up paying the bulk of the tax to maintain the aged, and/or taxes will be very high and punitive. Eventually the people and businesses that are here will get sick of working six months of the year to pay for other people's hospital visits so they will go too.
To counter this and to give us some tax revenue, we will have to liberate our migration policies. The 20,000 net migration we take in right now will have to at least double. That poses its own problems, not the least of which will be the skills, or lack thereof, these migrants will bring. If they're poorly skilled, wages will be low which will actually drain the economy rather than contribute to it. To balance this "draining" NZ will have to borrow. That is why you see the debt figures in 50 years time being absolutely horrendous. If we borrow lots and lots we will eventually go bankrupt and need bailouts by the IMF: a-la Iceland etc.
In simple terms, becuase it is so easy to move across the ditch, and because the old adage is people vote with their feet, unless we catch Australia, or get very close, we're stuffed. And I mean that.