Not to bring computer science into this, but in any system the chance for corruption increases with both size and complexity. New Zealand, while I'm very fond of it and a great admirer of it, is pretty small and notoriously hard to immigrate to.
The OP's comment resonates with my experience: I'm a Kiwi who's had family members immigrate, as well as talked to many friends and individuals who are trying to immigrate. It's definitely an immigrant-friendly culture (more so now than several years back), but that's not quite the same thing as "easy to immigrate to". Many of my acquaintances (from India, South Africa, and the EU) have found it very hard to find work here, extremely time-consuming and tiring to get through the visa process, and some have had to return home. I'm not saying it should be super-easy, and maybe it is easier than some other countries (I don't really know), but it's definitely not "easy" for most people I've talked with.
