How many foreigners come over with a large checkbooks from selling their houses from overseas?
NZ saw a huge influx of wealthy asian migrants in the 90s and early 2000s. But a fair % of them recently have fled to Australia. Actually there was a cut off date where kiwis could just migrate to Aus to take up permanent residency and this sparked a huge # of asians (around 1998 I recall). But then the decision was reversed so anyone in NZ could run to Australia.
The reason why property prices are falling down is there's fewer wealth migrants coming to NZ. Coupled with the leaky house syndrome. Just look overseas and wonder how housing prices are doing abroad? UK, USA, etc hasn't seen ANY rise in property value (in average) so it's no mystery why NZ would be any different.
The playing field of land ownership will never change in NZ for as long as politicians have a vested interest in owning land. This is by far a big difference to overseas where retirement for all (including politicians) are rooted from the stock market (pension funds).