amp.theguardian.com/commentisfree/2018/apr/30/new-zealand-sex-work-prostitution-migrants-julie-bindel
I have read before that part of the reason decriminalisation has been more successful (ie resulted in less trafficking) than in other places was because New Zealand is an island So it's harder to traffic into.
Looks like there just isn't enough supply so now you can use prostitution on your immigration forms.
Bleuch.